David Cameron’s efforts to form a new group of anti-federalist MEPs have run into difficulty within days of the European parliamentary elections.

After his pledge to quit the EU’s main centre-right bloc was criticised for isolating him from Nicolas Sarkozy and Angela Merkel, recent attempts to avoid xenophobic allies are causing friction with his Czech partner.

The Czech ODS, led by Mirek Topolánek, the former Prime Minister photographed naked at Silvio Berlusconi’s villa, wants as many parties as possible to join Mr Cameron’s group of MEPs to give it extra clout. But Mr Cameron is resisting the more populist candidates, such as Italy’s anti-immigrant Northern League and the similarly inclined Danish People’s Party (DPP).

While the Czechs have no objections to Umberto Bossi’s Northern League, the Tories fear that it would bring bad publicity.

One of the League’s MEPs, Mario Borghezio, was arrested at a banned anti-Islam rally in Brussels in 2007 and fined in Italy in 2005 for setting fire to the belongings of immigrants.

The DPP is understood to have asked to join the Conservatives but has been rejected, partly because of its opposition to Turkish membership of the EU. Still under consideration is Roberts Zile, of Latvia’s For Fatherland and Freedom Party. The party recently banned the city’s gay pride march and supports an annual parade in honour of Latvia’s Waffen SS veterans.

A Tory spokesman said: “We will not sit with racists or extremists.”

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