Ahead of the Hutton report Labour's high command has slammed Michael Howard as an unfit candidate for Number 10.

Following the opposition leader's attack on Tony Blair's conduct, senior ministers have taken to the airwaves to denounce the Tories' tactics.

In a series of Commons exchanges earlier this week, Howard accused the prime minister of appearing "desperately dodgy" over the Kelly affair.

But Labour's big guns have returned fire ahead of the publication of Lord Hutton's report on January 28.

Commons leader Peter Hain said Howard's attack on Blair was "distasteful".

"Throughout this procedure we have been very, very careful not to try and second guess Lord Hutton's report which is precisely what Michael Howard has done in the House of Commons in, I think, a very distasteful way," he said.

"I think the public will say this is the action of a sort of tired old barrister, with a very questionable client and a questionable brief, seeking to question the prime minister's integrity before the report has been published."

Hain denied that the prime minister had been evasive on the issue and insisted he would bounce back following the Hutton report.

"I think people want a prime minister who carries on in that fashion, who provides strong leadership, even if he takes knocks, even if he takes criticisms," he said.

"Compare that with the dreadful performance we had from Michael Howard on the Frost programme only a few minutes ago, where he was evasive, he didn't answer any questions and frankly he is unfit to be a candidate for a prime minister."

Health secretary John Reid also mounted a fierce attack on the Tory leader.

"By attempting to make short-term political capital on a range of issues, I think Michael Howard has put himself in a difficult position in the long term," he told GMTV's Sunday programme.

"You may get an instant headline, but you put yourself in the frame - he's now in it. Mr Howard, you called the prime minister a liar.

"If the independent judge shows that you're wrong, will you have the courage now, because you've put yourself in the frame, to admit publicly, and apologise publicly for calling the prime minister a liar when it is not the truth."