"I begin to wonder whether any of us can say anything about policy without it being interpreted by the media as something to do with a future, not yet declared, leadership election, " he told BBC Radio 4's World at One programme.

BBC: Budget 2013: Liam Fox urges spending freeze and tax cuts

Writing in the Mail on Sunday, the MP - touted by some as a future leadership candidate - said the coalition "is about to enter the last chance saloon" and must consider a radical programme of tax cuts, including phasing out employers' national insurance contributions.

BBC: UK Politics