The next time there is a debate over the merits of technology in football, spare a thought for the referees of Hackney Marshes. Every Sunday morning, these unsung anti-heroes of the grass roots game turn out in the traditional black of their trade to run the gauntlet of ridicule and abuse in every language that multicultural London has to offer, from Albanian to Yoruba. Forget about linesmen; down here you're on your own. No matter that you're 30 yards behind the action, struggling to run off a Saturday night hangover and that you'd need better eyesight than Superman to make a marginal offside call from this distance. Get it right and no one will thank you. Get it wrong and you're surrounded by Colombians casting aspersions on your mother's virtue in staccato Spanish.

Not that Johnnie Walker would have it any other way. "Personally I'm totally against technology," says the chairman of the Hackney and Leyton Sunday Football League. "You won't stop 'em arguing. I've always said, if you can't use it over the marshes why should it be any different in the Premier League?" In a corner of the car park on the East Marsh, Walker is arbiter and pacifier when disagreements boil over, patiently defusing the flashpoints of the morning with seen-it-all-before wit and humour. Walker has been living and breathing football on the marshes since a 1940s childhood spent roaming the adventure playground of the bombed-out East End. "The only time I was ever scared was when I saw all of London lit up after an incendiary attack," he says. "It looked like the whole place was on fire." He points to the pitches, goalposts stretching into the distance until they are the size of matchsticks. "They buried the rubble from the Blitz under there. It created wonderful drainage."

Still, even Walker, with all his experience, must be awed as a brooding Antoniu Mieroi storms towards him and unleashes a thundering, gesticulating tantrum that warms the air on a finger-numbing January morning. Back in Romania, Mieroi played professionally for nine years with Politehnica Timişoara and Juventus Bucharest. As a junior international, his career promised even more until a double leg break at the age of 16. He surely never imagined his playing days would end on the lumpen pitches of East London, but Antoniu, now 37, doesn't like losing any more than when he was kicking a ball for a living. "I can't take it with these referees anymore!" he rants. "Every week, always with us! I'm not coming back!"

A top-of-the-table clash between Mieroi's premier division-leading Real Romania and Lapton has just ended in acrimonious chaos with Real on the wrong end of a 3-1 scoreline. Lapton — younger, faster and playing up to their billing as champions — have been dominant but the balance has only decisively turned late in the game. First, the referee waves play on as Lapton's centre-forward breaks through on goal from what seems an offside position. A defender grabs his shirt somewhere near but not conclusively inside the penalty area. The referee points to the spot. Crowded by incensed Real players, he brandishes his red card defensively, before pocketing it unused. The penalty puts Lapton 2-1 in front and, with their opponents sulking, they race straight through and score again. But there's more controversy to come. In the dying seconds, Real think they've scored; this time, though, the referee has spotted an offside. Nobody, least of all the official, can know for sure if he's got it right, but it's a moot point. Antoniu marches off in the direction of Johnnie Walker. Clusters of players are arguing all over the pitch. It's not clear whether the final whistle has been blown but the game is over by consensus.

"Those Romanians, they do moan," chuckles Walker when everyone has calmed down. "I thought they were well beaten. Still, they had an excuse with the penalty because we were in line and he was about seven yards offside. Of course, I ribbed the referee about it. 'Don't you give offsides?' I said."

Real Romania are not your typical Sunday league football team. Antoniu, when he's not ranting about the failings of referees and threatening to quit, tells stories of playing alongside the likes of Marius Lăcătuş, the bowl-haircutted striker once coveted by playground collectors of Italia '90 Panini stickers, Ilie Dumitrescu and Iosif Rotariu. "He marked Maradona at the World Cup," Antoniu reminds me. "Very good player, like Makélélé. You don't see them many times in the match but they control the game." Is there another player in Sunday football, I wonder, who can boast of two degrees of separation from the Hand of God?

At 38, Luci Domincă admits his legs have gone, but in his day, the midfielder proudly tells me, he played for Vrancart Adjud, a lower-league side who took Steaua Bucharest to penalties in the last 16 of the Romanian Cup in 1993. Vrancart were two goals up in the shootout before collapsing to a 3-2 defeat. "Something happened and I don't want to talk about it," mutters Luci, shaking his head darkly. "It was Steaua... We were not supposed to win, if you know what I mean."

Twenty years Luci's junior, Sebi Dârlea still has professional ambitions. Growing up in Portugal, he played for Sporting's junior sides until he was 16. Since coming to London, he's trained with Chelsea's academy and is coached by the former Soviet international Sergei Baltacha. With his sure control and instinct for two-touch pass and move, Sebi displays the possession-minded virtues of the aspiring modern player, seeking an approving nod from a watching scout. For now though, he's down on the marshes — "learning to play with the big boys", as Real's player-manager and founder Liviu Lazăr puts it — between trials with teams in Belgium, Holland and the MLS.

Given the calibre of some of their players, it's hardly surprising that Real have established themselves as one of the teams to beat on the marshes. After joining the first division in 2008, they secured promotion straightaway to the premier division as well as reaching two cup finals. Last year they finished second, behind Lapton, and won their first silverware, the Arthur Daniels Senior Cup. Liviu, who played semi-professionally at the same time as paratrooping for a living in the Romanian army, now has the premier division title in his sights. "We're just trying to achieve something good for the Romanian community," he says. "This is one of the oldest leagues in England and we want to be a part of that history."

Until recently most of Real's players would have been wary of admitting — let alone drawing attention to — their nationality for fear of an immigration officer rather than a referee taking their name on a Sunday morning. Those who came to the UK before Romania's entry into the European Union in 2007 mostly did so illegally using fake passports. "Sometimes we were Italians, we were from Greece, we were from Portugal, from France, from Spain," recalls Liviu, who arrived in London in 2002. Many ended up as cheap labour on building sites. Working long hours for low wages, risking deportation and often sending every spare pound home to families, kickarounds in London's parks provided a distraction as well as a social network for a community still putting down roots. "Any time a new bloke came looking for work or somewhere to live, the other guys would help him because it was the same for them when they arrived," Liviu explains. "You'd hear guys on the building sites talking in Romanian. We play in this park, we play in that park... so Real Romania started from there."

There are plenty of hard men in Sunday football, but Liviu is not obviously one of them. Thoughtful and articulate, he speaks in softly accented English. Even on the pitch, although a centre-back, he plays with the composure of a continental libero, his brain now working harder than his 38-year-old legs. Matters of tactics and motivation are left to Antoniu, his more forceful and temperamental lieutenant. In a team with more than its share of players who could pick a fight with a corner flag, Liviu brings some much-needed sang-froid, a temperament perhaps born of necessity during stints as a peacekeeper in Bosnia and Angola, as well as on the streets of revolutionary Romania.

Liviu was two months into military school in December 1989 when Nicolae Ceauşescu was toppled from power in the bloodiest of that year's eastern European uprisings against communist rule. Sibiu, the city where he was based, was the scene of fierce fighting when gunmen loyal to the regime fired on protesters as they gathered outside the headquarters of Ceauşescu's hated secret police, the Securitate. Liviu's barracks across the street also came under attack and the soldiers returned fire. "I was 18 years old and I was scared," Liviu says. "It was crazy. We'd seen movies like Rambo and stuff like that and for a while it was commando time. We were shooting at everything. But I was a kid and any second you can be dead. I had colleagues who were killed."

More than two decades on, Romania has fallen a long way short of becoming the country that Liviu and his comrades must have dreamed they were fighting for. Under Ceauşescu, Liviu says, everybody had an apartment and a job, the schools were good and you could take holidays on the Black Sea or in the mountains. Nowadays, Romania ranks among the poorest and most corrupt nations in the European Union with rising unemployment and an ailing economy kept afloat by IMF aid. For many young Romanians, the greatest freedom bestowed on them by the end of communism has been the freedom to leave. Since 1989 Romania's population has shrunk by almost two million and the country continues to lose hundreds of thousands of people each year. "Romania is a sad country now," says Liviu. "I went home in 2009 for the first time since I left and there was a pothole in the exact place I remembered it 10 years ago. Nobody had fixed it and nothing had changed. Everything is worse there now." For Liviu's two young sons, London is the only home they've ever known. "The oldest one is six and he speaks Romanian quite badly. I'm always saying to him, 'Don't spell it like that', and correcting his grammar. But it's alright; there are better opportunities for him here. Maybe he'll go to an English university and then you can do anything with your life."

While the current generation of migrants can now live legally in the UK with their wives and families – and few display any desire to return home; "We're English now, only with funny accents," Luci jokes – working conditions for many remain as tough as ever. Liviu installs kitchens and bathrooms, regularly works 12-hour days, six days a week, yet by the standards of some of his teammates he has a comfortable life. Most of his players work on building sites – part of an estimated 11,000 Romanians earning a living in the British construction industry – and are self-employed to circumvent restrictions on the number of workers from Romania and Bulgaria which companies can employ. While that allows them to work here, it means they do so without the rights, protections and benefits enjoyed by permanent employees. Because of this, as an industry watchdog pointed out last year, migrant workers are far less likely to complain about unsafe conditions and far more likely to be the victims of accidents. While I was following Real, one of their young players, Alex Vaduva, was sidelined after stepping on a nail that penetrated three inches into his foot. Alex was back at work the next morning, but he missed football for a month.

Life at the sharp end of the UK's immigration debate can be unpleasant too; spend too much time reading right-wing newspapers and you could easily form an impression of Romanians as a benefit-scrounging criminal underclass. "Sometimes you get abuse on the building sites. Sometimes at football," Liviu says. "'Fuck off back to your country', 'fucking immigrants!', 'fucking gypsies', all of that stuff. Once we had some problems with an Irish team and I told them, 'You're exactly like me! You came here working for money!'" As a migrant, you quickly learn to develop a thick skin. "Everyone is blaming us but it's not our fault," said Luci. "It's your system. We just came here for a better life. I don't nick, I don't steal, I don't break bones or nothing. I'm just working for my family. It's as simple as that."

Having grown up in Clerkenwell's 'Little Italy' as the grandson of Italian migrants, Johnnie Walker has seen it all before. Football on the marshes has always reflected London's changing demographics, as well as the capital's social problems, he says. "My team — MG Sports — well, the MG stood for Mazzini-Garibaldi but you can't have a mouthful like that can you? You're gonna get some tackles. We got called all the names under the sun so I know what these boys like the Romanians have to put up with. It's nothing new; I tell them that when they think they're being persecuted. They called us Italian bastards and we survived. Sooner or later they all get into the swing of it."

It is another bleak morning, one week after the Lapton match, and a chill wind swirls over the marshes. Real's opponents today are Independiente, an all-Colombian side. The South Americans turn up late and shuffle lethargically onto the pitch padded in woolly hats, leggings and gloves, looking like they'd rather be in Cartagena. Real have soon built a comfortable lead with Antoniu choreographing the team's attacks with an array of angled passes, the archetypal midfield general. By the second half, with Independiente looking increasingly ragged and Real starting to lose their concentration, the game has deteriorated into a succession of niggly tackles and Latin handbags. When Real's sixth goal goes in from an offside position the Colombians implode, swarming angrily around the referee. There is some half-hearted shoving before the official picks up the ball and walks off, abandoning the match with 20 minutes to go.

"It was easy today," says a more contented Antoniu afterwards. "When they had the ball they just tried to do some skills to show you how good they were, but they didn't play as a team." I tell him that the game reminded me of Romania's 3-1 win over Colombia in 1994 – one of my favourite World Cup matches – and of Gheorghe Hagi's stunning strike from 40 yards that ranks among the tournament's all-time great goals. "Some people said Hagi did that by mistake. But I saw Hagi play in Romania when he was young – 17 or 18 – and he scored that goal three or four times," Antoniu says, drawing on a roll-up cigarette as he peels off his shin-pads. "We say in Romania, when Hagi kicked the ball you could put a glass of water on it and he wouldn't spill a drop. He was a genius."

Romania could do with a genius today. If the country's economic future looks grim, then the prospects for Romanian football, once so vibrant, appear equally bleak. For all its social and political ills — and despite the endemic match-fixing and allegations of drug-taking which tainted the era — communism raised the status of Romanian football; Steaua Bucharest were briefly one of Europe's great clubs, beating Barcelona to win the European Cup in 1986, as well as reaching another final and a semi-final. The 1994 World Cup, when Hagi led the last generation to emerge from the communist system to within Dan Petrescu's missed penalty of the semi-final, was the national team's finest hour, but Romania regularly reached the knockout stages of tournaments until Euro 2000, as England fans will painfully recall. Yet the present generation finished fifth in their group in their last World Cup qualifying campaign. With the team struggling to qualify for the Euro 2012 finals, it's safe to assume that border guards along Romania's frontier with Ukraine are in for a quiet summer.

Liviu blames the same talent drain that drives young, educated and ambitious Romanians west for the country's declining football fortunes. "You need to keep the young players in Romania, getting the games and the experience — just playing and playing. But now the agent is taking them to Italy and Spain at 18 or 19 and they're not getting a game. Once they're sitting on a subs' bench you've lost them. They're selling the young people — it's modern slavery."

Real Romania, at least, are flying the flag for their country's footballing pedigree with more success than their professional counterparts. A 2-1 revenge win over Lapton at the beginning of April, followed by a 6-4 victory over their nearest challengers FC Metwin, sets them up to clinch the title, inevitably yet anticlimactically, by that classic Sunday league scoreline: a 'walkover' in their final fixture of the season against phantom opponents Woodgrange Rovers, a team who haven't turned up for a game since 9 January. Already twice the age of some of the teenagers running around them on a weekly basis, Romania's senior players were probably grateful for the morning off. "Every summer, I say I'm not going to do that again," says Liviu with the resignation of someone who knows, despite the aches and strains, he'll be back in training come August, especially with a title defence to be plotted. "Because I miss my family on a Sunday. You spend a lot of time on the phone to the players, sorting out injuries or finding them work."

As for Luci, retiring gracefully, he concedes, is not an option: "I'll turn up one day and just embarrass myself in front of these kids. But I'm still mad to play; I play Tuesdays five-a-side, Fridays we have training, Saturdays seven-a-side and Sundays here. I work half-seven to five o'clock, even Saturday. My family sees me at night when I am in bed, but they understand me, thank God for that. I've got football in my blood, you know. I can't give it up."