Iain Duncan Smith has called on the prime minister to apologise to parliament for misrepresenting the status of the government's "dodgy dossier".

Tony Blair said the foreign secretary had already apologised to parliament for any mistakes and stressed that much of the content in the second dossier "was indeed based on intelligence".

But the opposition leader said that Blair was once again showing contempt for parliament on Wednesday.

"Why is it that for this prime minister that sorry seems to be the hardest word?" asked Duncan Smith.

Blair, however, had little time for the attack saying he "did not accept that parliament was in anyway misled at all".

And he countered that Duncan Smith had been given sight of the intelligence.

"The intelligence that we put forward was intelligence that was shared by him," said Blair.

The prime minister insisted that Duncan Smith was twice briefed by the head of the Joint Intelligence Committee - on September 18 and February 12.

Amid angry scenes in the Commons the opposition leader insisted he had never been briefed on the dodgy dossier.

"The prime minister knows I was given no sight of that dossier. The first I knew about that dossier in February was when I found it in the newspapers - so he can retract that for a start," he said.

"Until the prime minister accepts that he mispresented the status of the second dossier and apologises his trust will plummet and nobody will believe a word he says anymore."

Following the Commons exchange, the Conservative leader wrote to Downing Street to demand an apology.

"You said that the intelligence on which the dossier was based was intelligence that was specifically shared with me. That is completely untrue," he wrote.

"If you check your records you will find that immediately I read about the February document in the newspapers, I caused a telephone call to be made to your office asking for the basis of this document. I had no prior knowledge whatever of its contents or the material on which it was based.

"Furthermore if you check your records you will find that the last time I saw the head of the JIC was on the 18th September 2002 just before the publication of the first dossier. I did not see him again until the 12th February 2003, nine days after the second dossier was published.

"At no time was I given an oral briefing on the second dossier by the Intelligence services prior to its publication.

"Will you now withdraw this false allegation and apologise without delay?"