Duncan Smith in line for Hague's backing as leader

William Hague is expected to back Iain Duncan Smith in the election to choose his successor as leader of the Conservative Party.

Allies of Kenneth Clarke had hoped to woo Mr Hague, but the outgoing Tory leader will not be voting for the former chancellor, who refused to serve in his Shadow Cabinet because he could not accept Mr Hague's hard line on Europe.

Mr Hague is understood to have been irritated by Mr Clarke's stinging criticism of his leadership of the party as "four wasted years". He is also said to believe that a strongly pro-European figure such as Mr Clarke would have difficulty leading a party dominated by Eurosceptics. He opposes Mr Clarke's line on the single currency and his plans to end the Tories' opposition to the EU's Treaty of Nice and its rapid reaction military force.

Although Mr Hague is unlikely to announce his position publicly, one aide said: "He did not vote for Ken Clarke in the ballot amongst MPs; he will not be voting for him in the members' ballot."

Mr Duncan Smith has already won the public support of Michael Ancram, the former Tory chairman who was eliminated from the Tory race in the first round. He hopes to win the backing of Baroness Thatcher, who denied a newspaper report that she preferred Michael Portillo to Mr Duncan Smith.

But another former Tory leader, John Major, may come out in support of Mr Clarke, his former chancellor. Mr Duncan Smith was a thorn in the side of the Major government as one of the Tory MPs who rebelled over the Maastricht Treaty.

Allies of Mr Major deny that his opposition is a revenge attack for Mr Duncan Smith's rebellions. They say the former prime minister believes that the Tories should be led from the centre-right, and that Mr Duncan Smith is not the right man to lead the party back to power.

Yesterday, Mr Duncan Smith hit back at Mr Clarke's criticism that he was the "conservative with a small 'c'" candidate. In a message to supporters, he said: "The future of Conservatism lies in our own beliefs and values, not by throwing them away. However, the party must accept the need for change. We must broaden the base and the appeal of the party."

Mr Duncan Smith sought to change his image as the "natural heir to Norman Tebbit", whose Chingford seat he now holds, by saying: "We need to demonstrate that the party is open to all those who share our values – freedom, enterprise, responsibility and tolerance – but have too often found the party unwelcoming.

"But these changes will not be enough to reconnect the party with the British people and that is going to be the most significant challenge we face."

Campaign managers for the candidates held talks yesterday over a possible "holiday truce" so the two men could take a short break next month before resuming their campaigns.