Disquiet over Tory leader David Cameron's European policy surfaced among senior party figures yesterday as he faced a double-pronged assault over calls for a referendum on the new EU treaty.

Former Chancellor Kenneth Clarke said referendum demands had "an inner absurdity" and argued that moving away from Euroscepticism would boost Tory electability.

Mr Cameron claims the treaty, expected to be finalised later this year, preserves much of the planned EU constitution, rejected by Dutch and French voters in 2005 and has accused the government of breaking a promise to hold a referendum and of handing powers to the EU without permission from the public.

Conservatives renewed demands for a referendum after Irish foreign minister Dermot Ahern said it was "likely" a public vote would be held there. Speaking on GMTV's Sunday Programme, the strongly pro-European Mr Clarke advised: "One thing that will make a Conservative Party electable will be if we continue to dilute this absurd, extreme Euroscepticism that swept over the party in the last 10 years."

Mr Clarke, who chairs the party's democracy task force, continued: "I find the idea of a referendum on whether the Polish voting deal was the correct one and whether you should have a rotating presidency of the European Council has an inner absurdity."

Former Foreign Secretary Douglas Hurd told the programme referendums should be reserved for "the most extraordinary earthquakes which are proposed", adding: "I don't think there's anything in this treaty in so far as we can see it now which actually justifies that."

But he hailed Mr Cameron for "draining the poison" out of the European issue for Tories.