He said: “It has, but you see what I say to people is, ‘Why is it difficult in Iraq?’ It is not difficult because of some accident in planning, it is difficult because there is a deliberate strategy, al-Qaeda with Sunni insurgents on one hand, Iranian-backed elements with Shia militias on the other, to create a situation in which the will of the majority for peace is displaced by the will of the minority for war.”

Mr Blair’s frank remarks came on the day that one of his most loyal ministers was reported to have described the war as “his big mistake in foreign affairs”. Margaret Hodge was said to have accused Mr Blair of espousing “moral imperialism”, remarks that she denied through an aide but which were recalled by people who attended the private meeting at which she was alleged to have made them.

Mr Blair was speaking to Sir David Frost on the first edition of his Frost over the World programme on al-Jazeera International, which was launched on Wednesday. His appearance is a boost for the network, which was once denounced as propaganda by Donald Rumsfeld, the former US Defence Secretary, and is perhaps best known in Britain for broadcasting tapes from Osama bin Laden and al-Qaeda.

After his apparent admission that the intervention had been a disaster, he insisted: “We are not walking away from Iraq. We will stay for as long as the Government needs us to stay.

“And the reason for that is that what is happening in Iraq, as in Afghanistan, as elsewhere in parts of the Middle East, is a struggle between the decent majority of people, who want to live in peace together, and those who have an extreme and perverted and warped view of Islam, who want to create war. In those circumstances, our task has got to be to stand up for the moderates and the democrats against the extremists and the sectarians.”

Mr Blair also rejected as absurd suggestions that his readiness to work with Iran and Syria in the search for Middle East peace amounted to appeasement. He repeated his appeal to the two countries described by President Bush as part of an “axis of evil” to become partners for peace.

He said that he had a message for Tehran and Damascus: “If you are prepared to be part of the solution, there is a partnership available to you. But at the moment, and this is particularly so in respect of what Iran is doing in supporting terrorism throughout the Middle East and acting in breach of its nuclear weapons obligations, you are behaving in such a way that makes such a partnership impossible.”

Mrs Hodge, a Trade and Industry minister, also allegedly told a branch meeting of the Fabian Society that she had doubted Mr Blair’s approach to foreign affairs since 1998. According to the Islington Tribune newspaper, she singled out Mr Blair’s “moral imperialism” — exporting British attitudes and ideas to other countries — for criticism. She had accepted the Prime Minister’s argument about the dangers posed by Iraq before the March 2003 invasion because “he was our leader and I trusted him”.

The Islington Tribune said that Eric Gordon, its editor, sat in on the meeting of Islington Fabian Society, which was held last Friday at the London Resource Centre in Holloway Road. Mark Blunden, a reporter for the paper, said that Mr Gordon had taken a shorthand note of the alleged remarks and that the story had been checked thoroughly.

There were no questions over her future particularly after Mr Blair’s remarks.

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