Tony Blair yesterday attempted to use the uncovering of a mass grave near Baghdad to justify the war against Iraq.

The prime minister told MPs that the government was redoubling its efforts to preserve evidence of the brutal crimes of Saddam Hussein's regime.

Earlier, foreign secretary Jack Straw had played down the importance of finding Saddam's alleged stockpiles of chemical and biological weapons.

Speaking on BBC Radio's Today programme he said that the deposed Iraqi leader had had plenty of time to destroy the material used to make the weapons.

Yesterday Geoff Hoon told the Commons defence committee that there was "a range of detailed evidence demonstrating that Iraq was engaged in a determined way in the development of weapons of mass destruction".

The defence secretary, said: "We have found, for example, a large amount of protective clothing available to Iraqi forces, the only purpose of which would be to protect them from their own biological and chemical weapons. The coalition does not possess such weapons."