Tony Blair has described in detail how his support of Israel during the 2006 Lebanon war caused him substantial political damage and accelerated his departure as Prime Minister.

In his memoirs, A Journey, released this week, Mr Blair wrote that his reaction to the conflict "probably did me more damage than anything since Iraq. It showed how far I had swung from the mainstream of conventional Western media wisdom and from my own people".

Western leaders had initially "queued up to advise Israel to stand firm and hit hard", he wrote.

At the G8 summit in St Petersburg, which began as the conflict escalated, "there was a common belief that Hizbollah had it coming, and if Israel took them out, so much the better".

But when Israel stepped up its response, Mr Blair was pushed hard to encourage Israel to call a unilateral ceasefire.

Olmert was in a tricky position

He wrote: "There then came about a choice in politics which did me real and lasting damage. European opinion quickly solidified around the demand that the Israelis should stop.

"I felt it was wrong that there should be a unilateral cessation. It should be on both sides, and we couldn't expect Israel to stop unless the rockets stopped. But that was not how it seemed to most people."

Mr Blair recognised that Israeli PM Ehud Olmert was in a "really tricky position".

"The war went on longer than it should. The alienation of Israel from the international community became worse. As one of the few people ready to understand their point of view, I suffered accordingly."

Reflecting on whether he "should have just caved in and condemned Israel", Mr Blair acknowledged that the Israeli response was "at one level disproportionate" and he could appreciate the "manifest injustice suffered by the Palestinians".

But he concluded: "I was squeezed. But by then I felt truly uneasy compromising on it.

"If I had condemned Israel, it would have been more than dishonest; it would have undermined the world view I had come to hold passionately."

The failure to go against the Israelis meant Labour backbenchers moved "more or less en masse to a querulous position" and demanded he reveal his plans for leaving Downing Street.

The book also discusses the cash-for-honours row which saw Lord Levy arrested and questioned.

Mr Blair wrote that the donations system was a "murky business" and that from March 2006 until he left office it was "a running sore of the most poisonous and debilitating kind" and had been "18 months of hell for all concerned".