Tony Blair faced down opposition from the Cabinet and his own advisers in refusing to weaken his position on the Israeli bombing of Lebanon in the summer last year.

His stance, which aides admitted looked callous as he declined to call for an immediate ceasefire, was the last straw for many Labour MPs and left him open to the attempted coup against him only weeks later, according to Blair Unbound. That in turn finally led him to announce that he would leave office this year.

The book reveals an extraordinary conversation between Mr Blair and Margaret Beckett after he made her Foreign Secretary in his final reshuffle last year. He told her that her predecessors, Robin Cook and Jack Straw, had quickly lost the confidence of the Israelis and had never won it back. “If we are to have any real influence it is fundamental that you acquire their confidence and retain it,” he told her.

As Israeli action against Hezbollah targets in Lebanon intensified, Mr Blair stuck to his determination not to call for an immediate ceasefire. According to aides, he believed that Hezbollah had provoked Israel, which had an absolute right to self-defence. Mr Blair told Mrs Beckett: “Sounding off is nothing; it is what Chirac does.” At Mr Blair’s direction, she blocked moves to call for a ceasefire at a foreign ministers’ conference in Rome.

On July 27, unease surfaced at the last Cabinet meeting before the recess. Mr Miliband spoke about “the widespread concern about the damage that his line on Lebanon was doing to the party and its standing”. Mr Straw had told Mr Blair privately that he thought he was making a fundamental error “but found him unyielding”. Labour MPs were in a state of outrage and Ruth Turner, a senior aide, had the task of conveying the depth of it to him. “He was completely aware of the extent and depth of their anger.”

News broke on July 30 of the Israeli bombing of Qana, at which point Mr Blair’s most loyal foreign affairs advisers began telling him that it was time to “adjust our line”. He still refused the pleas to call openly for a ceasefire.

Mr Blair delayed his holiday to work for a UN resolution on Lebanon, which he achieved, but he had damaged himself badly. The PLP was in revolt and 100 MPs signed a letter calling for a recall of Parliament. Within weeks the coup against Mr Blair began.