Iain Duncan Smith pledged yesterday that he would not be "knocked aside" by Conservative dissenters.

Speaking on the BBC's Breakfast with Frost, the Conservative leader said: "I am a determined man and I'm determined to hold this government to account and nothing is going to knock me off on that. I'm determined to lead us. I'm not going to be knocked aside".

However senior backbencher Francis Maude told GMTV that the Conservatives are currently not a serious alternative to the Labour government.

"I don't think anyone seriously believes that we have yet done what needs to be done to make us a serious contender to be in government. Our problem is that we haven't, for some time, been a credible alternative government," he said.

Duncan Smith also used his interview to accuse Tony Blair of being personally responsible for Britain's problems.

"It is Blair who is responsible. He made personal promises and we have to hold him to account for that," he said.