On platform one at Bolton train station in England a mob of about 100 men punch the air in unison as a chant - "Muslim bombers, off our streets!'' - goes up. Their voices echo loudly, and as more men suddenly appear, startled passengers move aside. The protesters wave St George's Cross flags - the red and white English national emblem - and raise placards. Some wear balaclavas, others black-hooded tops. There is an air of menace.

These are some of the most violent football hooligans in Britain and today they have joined in an unprecedented show of strength. Standing shoulder to shoulder are notorious gangs such as Cardiff City's Soul Crew, Bolton Wanderers' Cuckoo Boys and Luton Town's Men In Gear: a remarkable gathering given that on a match day these men would be fighting each other. But today they are not here for football; it is politics that has drawn them. Their destination is Manchester to support a protest by the newly formed English Defence League.

The police are here in force, too. "Take that mask off," barks a sergeant to one young man. The man does so immediately but retorts: "Why are they allowed to wear burqas in public but we're not allowed to cover our faces?" The sergeant snaps back: ''Just do what you're told."

A man with a West Country accent standing next to me says: "It's always the fxxxxx' same these days. One rule for them and another for us. I'm sick of this fxxxxx' country." He draws on a cigarette before flicking it to the ground in disgust. He starts to complain again, but when the public address system announces the arrival of the train to Manchester Piccadilly, he raises his hands above his head and starts another football favourite: "Rule Britannia, Britannia rules the waves ..."

His companions join in singing, and as the train comes to a halt beside the platform the crowd surges forward. The carriages are almost full, so the men pack into aisles followed by police speaking into radios. A group of young men drinking beer at a table eye the protesters warily, but one protester wearing a baseball cap notices their fear and reassures them. "It's all right lads, nothing to worry about. We're protesting against radical Islam. Come and join us," he says, and as the train draws nearer to Manchester, the singing starts again. "Eng-e-land, Eng-e-land, Eng-e-land ..." the men sing rowdily. The English Defence League is in town.

A ready-made army?

The league seemed to spring from nowhere in 2009, but since its formation the far-right movement has held major protests in nearly all of Britain's cities. Although it claims to be a peaceful group, violence has erupted at most league demonstrations, with its supporters fighting on the streets against police, Muslim youths and a group called Unite Against Fascism, an umbrella organisation consisting mainly of students and trade unionists and formed in 2003 to oppose the far-right. During the fighting hundreds of people have been arrested, weapons have been seized and city centres have been brought to a standstill.

Britain has not witnessed such street violence for many years and there are growing fears that the league - despite its official multiracial stance - has become a ready-made army for neo-Nazis who for years have operated underground and that tensions will erupt resulting in major disorder.

All mainstream political parties in Britain have criticised the league, including John Denham, the former communities secretary, who compared the group to Oswald Mosley's Union of British Fascists, which ran amok in London during the 1930s.

Tinderbox northern towns such as Bradford and Oldham - which witnessed race riots in 2001 - have been among the league's targets this year and a countrywide police team set up to combat domestic extremism, the National Extremism Tactical Co-ordination Unit, has been investigating the movement.

I had met members of the league for the first time in a derelict building in Luton, near London, three weeks before the Manchester rally. They had agreed to talk on the condition that I did not identify them. Eleven men turned up. All wore balaclavas and most had black league hoodies with ''Luton Division'' on the back. A man using the pseudonym Tommy Robinson did most of the talking and explained the movement's background.

"For more than a decade now, there's been tension in Luton between Muslim youths and whites. We all get on fine - black, white, Indian, Chinese - everyone does, in fact, apart from some Muslim youths who've become extremely radicalised since the first Gulf War. Preachers of hate such as Anjem Choudary have been recruiting for radical Islamist groups in Luton for years. Our government does nothing, so we decided we'd start protesting against radical Islam, and it grew from there," he said.

With Islam Europe's fastest-growing religion - Muslim populations are projected to expand rapidly in coming decades - the group's fear that traditional British culture is under threat have been exacerbated.

Robinson could barely conceal his anger as he described radical Muslims protesting as the Royal Anglican regiment paraded through the town on its return from Afghanistan in May 2009. Following the incident, he and others set up a group called United People of Luton. After linking up with a Birmingham-based group called British Citizens Against Muslim Extremists and a group calling itself Casuals United, they realised there was potential for a national movement. Robinson said members wore balaclavas to protect their identities because league members had been targeted by Muslim extremists.

But although the league publicly espouses peaceful protest, there is growing concern over its secrecy and quasi-paramilitary appearance - as well as some of its membership. According to the international anti-fascist magazine Searchlight, far-right British National Party activists and other fascist extremists are at the core of the league. The publication's allegations have been backed by a former league member called Paul Ray who claimed that the group had been hijacked by the anti-immigration British National Party.

Then there is Casuals United. The group came to the fore about the time the English Defence League was formed. An unprecedented alliance of football hooligans, it was the brainchild of Jeff Marsh, a member of Cardiff City's Soul Crew who has been convicted three times for violent offences. This included a two-year jail sentence for stabbing Manchester United fans. Marsh has now taken a back seat, so the public face of Casuals United is fellow Welshman and Soul Crew member Mickey Smith.

Casuals United makes full use of modern communications and uses social networking websites such as Facebook to organise the 50 or so gangs that have been recruiting members around Britain. Other neo-Nazi groups, including the British People's Party and the British Freedom Fighters, have also participated in league protests, despite their opposition to the league's multiracial position.

A 'perfect storm'?

The high command of the league is much more astute than its foot soldiers, however, and distances itself from violence. In a Covent Garden pub I meet a computer expert from London called Alan Lake who runs a website called Four Freedoms. Last summer he contacted the league and offered to fund and advise the movement.

His aim, he says, is to unite the "thinkers" and those prepared to take to the streets. He describes this marriage as "the perfect storm coming together," adding that street violence is not desirable but perhaps inevitable. "There are issues when you are dealing with football thugs - but what can we do?"

He strongly criticises fascist organisations, however, and says that one of his conditions for backing the movement is that it does not associate with far-right groups. "There are different groups infiltrating and trying to cause rifts by one means or another, or trying to waylay the organisation to different agendas. The intention is to exclude those groups and individuals."

But while some league leaders may oppose fascism, there are others who seem to have no problem with extremism. At league protests in Swansea, Wales, skinheads chanted British National Party slogans and raised Nazi salutes. In Northern Ireland, according to Searchlight, loyalists have started an Ulster Defence League, backed by the former paramilitary group the Ulster Defence Association, while in Scotland, the hooligan Inter City Firm attached to Rangers football club helped set up a Scottish Defence League.

At an EDL protest in the city of Leicester, the movement's supporters pelted police officers with bottles, cans, bricks and coins resulting in 17 arrests. One police officer suffered a broken leg.

The EDL protest garnered the largest police deployment in Leicestershire since the miners' strike 25 years ago. Police deployed 1,400 officers from 12 forces to deal with around 1,000 EDL supporters and a counter demo of around 700 anti-fascists.

During the demo, the International Arts Centre Fabrika had to be evacuated, with journalists and staff making their escape through the back entrance as EDL protesters attempted to break into the building and smashed windows. The Leicester Mercury, a local newspaper, reported that there were also confrontations between the protesters and a group of Asian and black men in the Humberstone Road area, near St Matthew's, with pockets of fighting.

What is concerning many people in Britain is that the movement is becoming more organised and stronger and feeding off growing Islamaphobia. With its anti-Islam stance, the EDL has been gaining support from abroad. Pamela Gellar, the woman leading the protest against the Islamic centre near Ground Zero in New York, has backed the movement and EDL members were welcomed when they flew to the US to oppose the Muslim community's plans on the ninth anniversary of the 9/11 attacks.

Leader Robinson was refused entry at JFK airport, however, and taken into custody and flown straight back to the UK.

Support has also come from Europe and on October 30, the EDL joined forces with the newly formed French and Dutch Defence Leagues at an event in Amsterdam. The meeting, organised by the European Freedom Initiative, was promoted as a demonstration for freedom and in opposition to Sharia. It was planned to coincide with the end of Dutch politician Geert Wilders' trial for hate speech and inciting racism.

The fears are, however, that European cities could soon be witnessing the widespread violence being experienced in Britain.