Tony Blair’s senior lieutenants talked him out of promoting Charles Clarke to the Foreign and Commonwealth Office in his last “botched” reshuffle, it is disclosed today.

Mr Blair then got cold feet over his inclination to make David Miliband his Foreign Secretary instead of Mr Clarke, and opted, to the disappointment of many in No 10, for Margaret Beckett. The way that Mr Blair’s last reshuffle, planned for months to avoid the chaos of previous reorganisations, went wrong is told in Blair Unbound, by Anthony Seldon, the latest biography of the former Prime Minister. It was regarded as a disaster by his own supporters because of his failure to promote enough Blairites.

The reshuffle had been perceived by many as Mr Blair’s last card, his way of regaining his authority after what had been expected to be bad local election results in May last year. Hours were spent in No 10 in the spring planning it. His team knew he had a poor reputation as a shuffler of the pack and were determined to make his final one his best. “The planning that went into the reshuffle was quite extraordinary,” an aide said. “All the civil servants and the Cabinet Secretary said that they had never been involved in anything quite like it.”

Mr Clarke, who Mr Blair had intended to replace Jack Straw at the Foreign Office at this point, had become embroiled in the row over the release of foreign prisoners. Even so Mr Blair favoured making Mr Clarke Foreign Secretary, the book says. “But the senior staff in No 10 took a very different view and now set about changing the Prime Minister’s mind. ‘No one had it in for Charles, but we said that it would look very awkward politically to promote someone who was thought to have made such a mess of something’. Another aide said more bluntly: ‘If things are ballsed up that badly, the public expects someone to take responsibility for it. We had to overcome Blair’s sense of personal loyalty’. Clarke had lost the confidence of Blair’s lieutenants, who had now won over their boss. His position as Home Secretary had become untenable.”

As is known, Mr Clarke then turned down Mr Blair’s offer that he should become Defence Secretary instead.

The book says that Mr Blair’s decision to move Mr Straw had been taken months earlier. Mr Straw had had differences with his Prime Minister over Iran, Iraq and whether Britain should be talking to Hamas. He became Leader of the Commons.

Many in No 10, including Sally Morgan and Matthew Taylor, his policy chief, wanted Mr Miliband to be Foreign Secretary but, after telling colleagues that it would be an appointment to renew the party, he slept on it and decided by morning that it would be too risky because Mr Miliband had been in the Cabinet for only a year. Mrs Beckett’s appointment angered many around Mr Blair, and Mr Miliband’s move to replace her at the Department for Environment, Food and Rural Affairs initially had him “bristling with rage” because he had work to do at the Department for Communities and Local Government.

Far from strengthening Mr Blair, the reshuffle weakened him. “The reshuffle was disastrous. Even our own people could not understand what on earth he was doing,” one close supporter said. Antagonism focused on the sacking of Mr Clarke but not John Prescott; the promotion of Mrs Beckett but not Mr Miliband; and the promotion of some Brownites but not sacking others.

“It looked like a desperate act,” one Blair aide said. Another said: “The reshuffle was his last bolt. Once he had shot it, he had nothing left.”

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