Cameron rules out Tories' 'dream ticket' with swipe at Clarke

The 38-year-old shadow Education Secretary ruled out a "dream ticket" under which he would back Mr Clarke, 65, in the hope of taking over from him as party leader after serving as his deputy for a few years.

Mr Cameron sought to bolster his appeal to the Conservative Party by contrasting his Eurosceptic credentials with Mr Clarke's pro-European instincts. Although Mr Clarke has tried to neutralise the European issue by saying he could not see Britain joining the euro for 10 years, Mr Cameron said yesterday: "We don't agree on Europe, which is a very important issue facing the future of this country."

Mr Cameron added: "He [Mr Clarke] believes we should have an ever closer union of European states and I believe we need a new sort of Europe, much more open and free-trading, more flexible and we should be returning some powers to nation states." Mr Clarke's determination to enter the contest threatens to undermine Mr Cameron's pitch for the votes of the Tory left and could turn the contest into a run-off between Mr Clarke and the front-runner David Davis, the shadow Home Secretary.

Mr Cameron rejected pressure from senior Tories, including Lord Heseltine, for him to withdraw and back Mr Clarke. "I'm not interested in tickets and deals. I'm interested in ideas and approaches and trying to get the right approach for the future of this country," he said.

In a controversial note, Mr Cameron argued that all Britons, including immigrants who have lived here for years, should have a duty to learn to read and speak English. He criticised local authorities for printing leaflets in ethnic minority languages, saying the effect was "to almost encourage the belief that learning English is not necessary".

Mr Cameron said Britain should withdraw - perhaps temporarily - from the European Convention on Human Rights if it was preventing the deportation of foreign nationals who may pose a threat to the country.