On the Le Pen menu: roast beef and raw bigotry

The notice reads like an invitation to a Rotary club dinner. Men are required to wear bow ties and dinner jackets, ladies "suitable frocks", and guests will dine on a traditional menu of Welsh vegetable soup, roast beef and apple pie.

The notice reads like an invitation to a Rotary club dinner. Men are required to wear bow ties and dinner jackets, ladies "suitable frocks", and guests will dine on a traditional menu of Welsh vegetable soup, roast beef and apple pie.

But tonight's £50-a-head banquet, billed as the "patriotic Dinner Event of the year", is not a charity fund-raiser. The guest of honour will be Jean-Marie Le Pen, the French fascist, who will address an audience of British National Party members following an invitation from Nick Griffin, the leader of the BNP.

This is the first time M. Le Pen, who once described the Holocaust as "a mere detail of history", has openly supported the BNP, and his visit, engineered to boost the far right's election prospects, has provoked outrage. Hundreds of protesters are set to demonstrate in Birmingham ahead of the dinner, which is being held in Shropshire at a secret location to prevent demonstrators disrupting the event.

Last week, David Blunkett, the Home Secretary, warned M. Le Pen, the leader of the Front National, that he faces arrest if he stirs up racial tension during his visit to Britain, which was revealed by this paper three weeks ago.

"If he incites, if he fosters hate, if he causes a disturbance or public disorder, then the police will take appropriate action," he said on Friday.

The BNP believes it has achieved a great publicity coup in securing the visit of M. Le Pen, a mainstream politician in France, and that it boosts its own credibility. The Le Pen visit comes a week before Britain opens its borders to migrants from 10 accession countries that join the EU on 1 May. It will fuel concerns that Britain's far-right movement is using fears over immigration to make political gains.

But an investigation by The Independent on Sunday has revealed that the BNP is plagued by splits, defections and sleaze, which undermine its attempts to create a broader, more respectable image. The BNP, which believes in the "voluntary resettlement" of "immigrants", told this paper it had been "overwhelmed" with public support, especially in reaction to asylum-seekers. So great is this support, a spokesman said, that new phone lines are being installed to cope.

According to the BNP, membership stands at about 10,000. Other sources suggest the real figure is fewer than 6,000 and that the party is woefully short of funds for the forthcoming European and local elections.

At present, the BNP has no MEPs or MPs but holds around 15 council seats across the country. Its greatest representation is in Burnley, Lancashire, where it holds six seats out of 45 and where, until recently, observers were worried the BNP would take hold of the council and could also win the parliamentary seat. A series of scandals and resignations has meant these fears have receded. A by-election had to be called in the Lanehead ward after Luke Smith, the BNP councillor who has a conviction for football hooliganism, attacked a fellow BNP member with a beer bottle.

Last month, Maureen Stowe, 65, a BNP councillor in Burnley, resigned from the party. "I've never been a racist," said Ms Stowe, who is now an independent councillor. "I didn't agree with a lot of what was being said by the BNP and found the party badly organised ... When you come in with big ideas, you have to live up to them and they haven't."

Outside a few key areas, the BNP has little party organisation. Those branches that do exist are reported to have few party activists.

Gerry Gable, the publisher ofSearchlight, an anti-fascist magazine, said the BNP's performance since the 2002 elections has been "pretty dismal". "Since May 2003 the BNP has fought many more than a dozen elections and won two. In my book, that's not a winning streak."

The criminal pasts of many members, including senior officials, also makes it difficult for the BNP, formed in 1982 by the right-wing extremist John Tyndall to shake off its pro-Nazi, bully-boy image.

Nick Griffin, who will sit next to M. Le Pen at tonight's black-tie dinner, received a two-year suspended sentence in 1998 for inciting racial hatred. His magazine, The Rune, carried obscene, anti-Semitic and Holocaust denial material, as well as crude racism.

Colin Smith, the party's south-east London organiser, has amassed 17 convictions for burglary, theft, stealing cars, possession of drugs and assaulting a police officer.

And Tony Lecomber, the BNP's group development officer, was convicted on five counts for crimes under the Explosives Act in 1985. He was handed a three-year prison sentence for offences that included possession of home-made hand-grenades and electronic timing devices.

In 1991 he notched up another three years' imprisonment for his part in an attack on a Jewish schoolteacher who Lecomber found trying to peel off a BNP sticker. His sordid history clearly slipped the mind of Mr Griffin when he was grilled by the BBC's Panorama programme three years ago. He said Lecomber's only conviction was for handling fireworks.

Politicians and anti-racism campaigners have been quick to expose the reality behind the party's new image. Alice Mahon, MP for Halifax, said the BNP liked to "prey on people's fears. These people dress in smart suits but underneath they are the same ugly human beings trying to bring division wherever they go," she said.

Sir Herman Ouseley, a former head of the Commission for Racial Equality, joined in calls for M. Le Pen to be banned. "We need people like him like a hole in the head," said Lord Ouseley, a Labour peer. "We should not let him in. He is someone committed to destroying people because he stirs up racial hatred."