Tory leadership hopeful Mr Iain Duncan Smith was yesterday distancing himself from the support of a right-wing Eurosceptic Conservative group.
The hardline conservative Monday Club had written to its members dismissing Mr Kenneth Clarke as a "Euro socialist" and calling for them to vote for Mr Duncan Smith, The Times reported.
As Mr Duncan Smith returned to the campaign trail in Bristol yesterday, his aides were quick to distance themselves from the support of the controversial group.
A spokesman for the shadow defence secretary said: "Iain Duncan Smith has not called for the backing of the Monday Club, he has never been a member of the Monday Club, has never spoken for the Monday Club and has not backed the Monday Club at any time."
Last night, Mr Duncan Smith turned the focus on to the Liberal Democrats and promised that if he became leader he would set up a new unit to tackle the threat from Mr Charles Kennedy's party.
"We have been suffering against the Liberal Democrats and this is basically a case of all-out attack that will start immediately after Mr Duncan Smith wins the leadership. It will be a bid to wipe out the Liberal Democrats," said a spokesman for Mr Duncan Smith.
The leadership hopeful said he wanted parliamentary candidates in all Liberal Democrat-held seats by early next year.
Yesterday, Mr Duncan Smith took part in a teleconference with party supporters. Conservative councillors around the country were able to call in and question him about the leadership race.
Mr Clarke said yesterday he believed the Tories would have the best chance of getting back in power if they were led by him.
"I personally like to think that the Conservative Party has the best chance of winning any election if led by myself. Everybody taking part in this campaign is concentrating on putting the campaign to the grassroots and to win - not just the general election, but every election up to that, because that is a very important part of us getting back to power."
Mr Clarke started his renewed leadership campaign trail in London and is about to embark on a 70-event nationwide tour. London, scene of widespread Conservative defeat in the last general election, would be a key battleground in the party's quest to claw back support nationally, he said.
A vital part of that would be to re-examine the devolved powers of the London mayor and make him more accountable.
The efficiency of devolution in the capital had also been hampered by the Government's "complete indecision" over its part-privatisation of the London Underground, said the former chancellor.
If his leadership campaign was successful, he would strive to "make clear" the mayor's powers.