Buoyant Cameron looks east to find Eurosceptic friends

The Tories aim to form a new Eurosceptic grouping at Brussels drawing heavily from former Iron Curtain countries by the end of the month.

Following his party's strong showing in the European elections, David Cameron, the party leader, made clear he remained determined to press ahead with the controversial move.

The Conservatives will be filling 25 of the 72 British seats in the Brussels parliament after they picked up 27.7 per cent of the popular vote.

The party performed strongly across England and Wales, although its vote fell slightly in Scotland, and even topped the poll in Wales for the first time since the 19th century.

Mr Cameron is now preparing to ally the Conservatives with right-wing parties in Poland and the Czech Republic opposed to closer European integration. Other potential partners could be sought in Belgium, Bulgaria and Latvia.

Internal critics warn that the move to pull the party out of the main centre-right grouping in Brussels – the European People's Party – could marginalise it. But senior Tories insist the new grouping, with the Conservatives filling the largest bloc of seats, will more accurately reflect the party's anti-federalist agenda.

One of its potential partners – the Law and Justice party in Poland – has been accused of tolerating discrimination against homosexuals.

Vaclav Klaus, the founder of another possible ally – the Civic Democratic Party in Poland – has questioned climate change.

Under EU rules, a political grouping has to have at least 25 MEPs drawn from seven countries to qualify as a "group". Some Tory MPs have questioned whether Mr Cameron can find politically unembarrassing partners from that number of nations.

However, a senior party official insisted last night: "We are very happy with the numbers."

George Osborne, the shadow Chancellor, told the BBC: "We are going to form a strong group in the European Parliament. We hope other people will come and join us."

The Tories declared themselves satisfied with their showing in the European election, even though their vote share only rose by one percentage point compared with the last elections to the Brussels parliament.

The party was hit, however, by the Commons expenses row which featured lavish claims by Conservative MPs. The UK Independence Party (Ukip) appeared to have won over hundreds of thousands of disaffected Tories last week; the Cameron team is optimistic that they will come back on board at the next election.

The Tories came first in 17 Welsh parliamentary constituencies, including Labour-held seats like Alyn and Deeside and Wrexham.

Mr Cameron said: "There will be a great toppling of Labour MPs if these results were copied at a general election. He said voters were leaving Labour having been "treated like fools" by the Government and were now "responding to the values of the modern Conservative Party".