David Cameron branded the prime minister a "complete phoney" today as he clashed with Gordon Brown over unemployment at Commons question time.

The Tory leader was ordered to withdraw the remark by the Speaker, Michael Martin, but not before Cameron claimed Brown was "in denial" about the state of the British economy.

Cameron's attack came after Brown had contrasted comments made by the shadow chancellor, George Osborne, and the shadow business secretary, Ken Clarke, over the Tories' plans to tackle the recession.

The Tory leader said: "I'm glad you are back to reading out quotations. We now know how long a pledge from you lasts. Yesterday you said in the Guardian, 'I personally have always said that modern politics, with its focus on who said what, when and how, is far too divisive to meet the problems of the country'. What a complete phoney!"

Amid uproar, the Speaker instructed Cameron to "properly withdraw" the remark.

The barb from the Tory leader is all the more remarkable since Brown had prefaced his remarks by talking emotionally about the death of Cameron's son, Ivan, three weeks ago.

In the most combative dispatch box exchanges for weeks, the Conservative leader claimed that there was now an "enormous gulf" between what Brown said each week and what the government was actually doing.

He again urged the prime minister to admit he was wrong to have claimed that Britain was best placed to withstand the recession and said Brown was "incapable of admitting he ever got anything wrong".

The prime minister hit back, claiming a Tory government would do nothing to help those at risk of losing their jobs.

Brown said of the Tory leader: "He asks us to do more by saying he will spend less and it just doesn't add up."

Earlier, the prime minister told the Commons it was a "matter of personal regret for me and the whole government" if people lost their jobs or were in fear of doing so.

Brown said the government would do "everything we can" to help people get back into work.

Cameron said the rise in the claimant count announced today, of 165,000 in the three months to January this year, was the highest since records began. Unemployment has now topped 2 million.

"Doesn't this show that his [Brown's] claim that Britain is well placed to deal with the recession is nonsense?" Cameron asked.

Brown said he came into politics to help people who were unemployed and argued that unemployment was higher in other countries such as France and Germany.

"I know that's of little comfort to people here, and that's why we're doing everything we can to help them," Brown said, adding: "We are spending £1.3bn helping people get into work; if the Tories feel strongly about this, why won't they support government spending plans?"

Cameron retorted: "There seems to be an enormous gulf between what he says every week and what the government is doing; he is incapable of admitting he ever got anything wrong."