Charles Kennedy has accused the prime minister of failing to "play it straight" with the British public over the reasons for going to war with Iraq.

Speaking in the Commons on Wednesday, the Liberal Democrat leader questioned why warnings by the Joint Intelligence Committee that the threat of terrorism could increase as a result of military action were not made public.

"Last September and again this February, the prime minister released dossiers to the British public, which included the intelligence assessments underpinning the case for war in Iraq," he said."Now why did he choose to withhold from those dossiers information which would have undoubtedly undermined his case in the minds of the British public?"

Tony Blair rejected claims that inclusion of the warnings in the dossier would have been a setback to the case for war.

"In my view, it would be completely and totally irresponsible if we were to say that the danger of those weapons falling into the hands of the terrorists meant we should allow Saddam Hussein to carry on developing them," he said.

"I think that would be a completely foolish state of affairs to have brought about, and that is the reason I do not believe it undermined the case for war at all."

However, Kennedy claimed that the government had not trusted the government "to form a balanced judgement on these matters".

"We now know that the prime minister, as he says, was warned by intelligence chiefs that war in Iraq could increase, rather than decrease, the risk of terrorism," he said.

"We now know...that the line in the original draft of the September dossier, which reassured our public that Iraq was incapable of launching a nuclear strike against Britain, that was removed before publication."

"Why didn't he play it straight with the British public at the time?" Kennedy asked.

In response, the prime minister launched a withering attack on Lib Dem policy.

"All I can tell him, if he wants it straight, is that the day we have the foreign policy of this country run by the Liberal Democrats is the day this country really would be at risk," said Blair.