TONY Blair’s top legal advisor changed his mind to authorise the invasion of Iraq after allegedly being “straightened out” by the White House.

In evidence to the Chilcot Inquiry yesterday, former attorney general Lord Goldsmith said talks with aides of President George Bush were the key factor in his decision to give what he called the “green light” to war.

Two days before Mr Blair’s appearance before the inquiry, Lord Goldsmith said he warned the former Sedgefield MP in late January 2003, just weeks ahead of the invasion, that a second United Nations resolution was necessary to authorise the use of force.

But his view changed after he flew to America for talks with a group of US officials and legal officers, including national security advisor Condoleezza Rice.

The meeting took place on February 10. Two days later Lord Goldsmith concluded there was a “reasonable case”

for war without a fresh UN mandate.

One of those present, President Bush’s legal advisor John Bellinger, allegedly said: “We had a problem with your attorney general who was telling us it was legally doubtful under international law.

We straightened him out.”

The revelation will be seized on by opponents of the invasion, who have criticised Tony Blair’s government for acting as America’s “poodle”

in the rush to war.

However, the testimony eased some of the pressure on the former prime minister ahead of his appearance tomorrow because Lord Goldsmith fiercely denied allegations that No 10 bullied him into changing his mind.

In the most colourful section of six hours of questioning, he rejected a claim that he was “more or less pinned to the wall” by Lord Falconer and Baroness Morgan and told “what Blair wanted”.

Lord Goldsmith protested: “Absolute and utter nonsense.

When I spoke to them I had reached my opinion.”

Instead, the Washington meeting emerged as the crucial reason for the former attorney general’s U-turn, which came as a second resolution became increasingly unlikely because of French and Russian opposition.

Lord Goldsmith became convinced that a key section in the first resolution (1441) – which used the word “consider”, not “decide” – meant war could be authorised after a discussion, without a vote.

However, he admitted the White House legal officers produced no evidence to back up their claim that France also believed that a second resolution was unnecessary.

Sir Roderic Lyne, a member of the five-strong inquiry panel, asked: “They couldn’t give you clear evidence of this? You had to take their word for it?”

He replied: “Yes I did. It was impossible to ask the French government what its view was because that would have weakened the West’s resolve to act in the eyes of Saddam Hussein.”

He insisted a reasonable case for war meant a green light, although it did not guarantee that a court would later agree that conflict was legal.

Just days before the war, his advice was firmed up to state it was definitely legal after the military demanded an unequivocal yes or no, but not, Lord Goldsmith insisted, because of pressure from No 10.

Last night, Mr Bellinger described the claim that he had had to stiffen the backbone of Lord Goldsmith as preposterous.

The inquiry is likely to return to the issue of the war’s legality when it quizzes Mr Blair tomorrow