From the BBC:
Two of Mr Straw's former cabinet colleagues, Clare Short and Robin Cook, have already said the public were misled.
Shadow foreign secretary Michael Ancram said Mr Straw's evidence had "left Alastair Campbell out to dry".
"If the government's credibility is to be established, it is vital that Alastair Campbell answers the relevant questions openly and completely and does not seek to hide the truth in a miasma of clever words."
Liberal Democrat foreign affairs spokesman Menzies Campbell said there was a sense of "not me guv" which would make Alastair Campbell's questions session something like "high noon".
He said the intensity of Mr Blair's speeches had left nobody doubting the immediacy of going to war, despite Mr Straw's insistence the words "immediate" or "imminent" were not used about the Iraqi threat.
I continue to be amazed, first at the power of opinion which has now forced parliamentary inquiries in 3 of the 4 coalition countries and second at the tortured arguments being used to prove that a large arsenal of WMDs ready to fire at 45 minutes' notice is somehow not an immediate or imminent threat. US Senator Byrd has again laid out some of the more salient quotes, the non-immediate, non-imminent and non-threatening ones.