A convicted Holocaust denier was one of the guests invited to speak at a British National Party meeting this week about how the party could make further progress in Europe.

Bruno Gollnisch, a French MEP and vice-president of the far-right National Front party, spoke at the Rembrandt Hotel in Knightsbridge, Central London.

The meeting came three days before Britain was due to vote in local elections. He appeared with Austrian MEP Andreas Mölzer, expelled from the country’s Freedom Party for being too extreme, and Georg Mayer, an Austrian Freedom Party officer.

The event had originally been billed by the BNP as a press conference, scheduled to include the party’s leader Nick Griffin and its mayoral candidate, Richard Barnbrook. But this was cancelled and a closed meeting was held instead. Mr Griffin and Mr Barnbrook are understood to have been present at this meeting.

Gerry Gable, publisher of anti-fascist magazine, Searchlight, was told of the European delegates’ visit by a mole in the BNP before the press conference was announced last week by Simon Darby, the party’s deputy leader.

Mr Gable said: “Searchlight’s mole… was convinced that this was a smokescreen to cover up Darby’s breach of security in publicising the event so far in advance.”

Searchlight, which has worked for months to expose the BNP’s actions in advance of the local and mayoral elections, was particularly incensed in view of the party’s determined courting of Jewish voters.

Mr Gollnisch was sentenced in France last year to a three-month suspended prison sentence, and was fined €5,000 (£4,000) for denying the Holocaust. The court found that he had “disputed a crime against humanity” in comments he made at a news conference in October 2004.

Mr Gollnisch had questioned the number of Jews who died in the Holocaust and said the “existence of the gas chambers was for historians to discuss”.

Andreas Mölzer is the publisher of Zur Zeit, an Austrian political journal. Mr Gable said of the publication: “Racism, antisemitism and xenophobia are staple features. Its recent promotion of openly Nazi and antisemitic books prompted the Berlin weekly Junge Freiheit, on which Zur Zeit was originally modelled, to sever all connections.”

Georg Mayer was the spokesperson for the far-right group Identity, Tradition, Sovereignty in the European Parliament, until its collapse late last year.

Mr Darby this week admitted that the meeting was about “what we [the BNP] are going to do in Europe.

“The European elections are in 12 months. There’s a group in the European Parliament that represents nationalists, and the way votes are going now, there’s a real possibility we could be involved in that.”

He added: “There’s nothing wrong with us discussing things with elected representatives.”

But he would not comment on the party’s decision to host a convicted Holocaust-denier.

“I can’t discuss the Holocaust because I could be extradited to France or Germany, if what I’m saying is interpreted in a certain way,” he said.

A spokesman for the Community Security Trust said: “I think the BNP’s courting of these notorious individuals proves once again that their claims to respectability are entirely fraudulent.”