Hewitt may replace Hoon

Tony Blair is ready to appoint Britain's first female defence secretary if Geoff Hoon is forced to quit by the Hutton Inquiry.

He is lining up Trade Secretary Patricia Hewitt for the role after accepting that the investigation is likely to force unwanted changes to his Cabinet.

Mr Hoon is a central figure after he was accused of authorising the release of David Kelly's name to the media during the hunt for the source of claims by the BBC that the Government exaggerated the threat posed by Iraqi weapons.

He has attracted a range of criticism - not least for opting to go on a family holiday to the US at the time of Dr Kelly's funeral last week.

Senior figures close to Mr Blair have privately accepted that there is virtually no chance that Mr Hoon will survive in his post after the publication of the report in the autumn.

That will mean an unwanted Cabinet reshuffle for the Prime Minister.

But he is determined to plan ahead and not be caught out by events as he was during June's reshuffle which saw him under attack for a series of bungles.

At one stage, Mr Blair had considered Ms Hewitt as health secretary but changed his mind at the last minute and installed leading

Labour bruiser John Reid in the tricky post. Since then, Ms Hewitt has made a number of wide-ranging speeches and interventionssuggesting she is gearing up for a change after having been in charge of trade for two years.

In one controversial set of comments, she attacked New Labour's obsession with centrally-set targets across the public services, leading to claims they were about to be scrapped.

She is thought to have performed well as Trade Secretary and to deserve a move to the MoD, traditionally one of the Cabinet's most demanding posts.

Her first task would be to restore the department's reputation and morale, which both took a heavy blow after Dr Kelly's death. If she wins promotion, it will be another step forward for the "Kinnockites" within the Cabinet - Ms Hewitt was the former Labour leader's press secretary.

Elected an MP in 1997, she joined the Cabinet as Trade Secretary four years later.

But she had served her time in the tough world of Labour politics in the Eighties, a true baptism of fire as the party faced seemingly endless civil strife and years in opposition. While working for Mr Kinnock, she played a crucial role defending him while he was savaged by sections of the media, an experience which prepared her for anything Whitehall could throw at her.

Unlike many ministers, Ms Hewitt has some business experience, working as director of research for Andersen Consulting for three years in the Nineties.

Born in Australia, Ms Hewitt, 54, was educated at Canberra Girls' Grammar School. She has won a reputation as a calm operator. A minister who has worked closely with her said: "She is very good. She is unflappable and she doesn't take any rubbish." She is married with a son and a daughter.

Westminster insiders say her job could be filled by former agriculture minister Jack Cunningham, who is being tipped for a surprise return to the front line four years after leaving the Cabinet.

The Prime Minister is understood to regard him as the ultimate "safe pair of hands" to guide a big department through until the next election. The two men are thought to have dined together last week during the Prime Minister's family holiday in Barbados.