Blair was dubbed "reckless" by Short
Tony Blair is risking his own legacy because he is "increasingly obsessed with his place in history", Clare Short has said after quitting the cabinet.
The international development secretary resigned on Monday morning, accusing Mr Blair of breaking promises over Iraq's future.
She used her resignation statement to launch a scathing broadside against the "presidential" style of the New Labour government.
Trust was being undermined and party loyalty strained by the kind of errors seen over Iraq, she told MPs.
"There is no real collective responsibility because there is no collective - just diktats in favour of increasingly badly thought through policy initiatives
that come from on high", she continued.
Ms Short also complained that she first learnt of the detail of a new UN resolution on rebuilding Iraq from BBC News Online, when her department is supposed to have a key role in the country's reconstruction.
She said the drafting of the resolution had been shrouded in secrecy.
That suggestion was rejected by Foreign Secretary Jack Straw, who said the UN process was open and that the draft resolution would give the UN a "vital role".
Ms Short's replacement is Baroness Amos, the Foreign Office minister who has been the government's spokeswoman on international development in the House of Lords.
Ms Short had threatened to quit before the start of war with Iraq, describing Tony Blair as "reckless" during the build-up to military action.
But she decided to stay because she believed leaving when war was unavoidable would be "copping" out.
Ms Short called the prime minister to tell him of her decision to resign just 20 minutes before the news was announced.
She says her position was made impossible because the draft new UN resolution now being discussed at the Security Council does not give the UN its promised central role in rebuilding Iraq.
She called the UK's position "totally dishonourable".
"I cannot defend it. It is wrong in international law and for the rebuilding of Iraq and it breaches the promises that the prime minister gave to me," she told BBC News.
She warned that the UK was colluding in a resolution which could perpetuate international divisions, marginalise the UN and make it more difficult to rebuild Iraq.
In her resignation statement to the House of Commons, Ms Short said the UK Government was supporting the US "in trying to bully" the UN Security Council into adopting the resolution.
Mr Blair was not in the packed and tense House of Commons to hear Ms Short go well beyond Iraq in her bruising attack.
"To the prime minister, I would say that he has achieved great things since 1997," she said.
"But paradoxically, he is in danger of destroying is legacy as he becomes increasingly obsessed with his place in history."
She predicted Labour was entering "rockier times" when MPs would need to prevent the government departing from the party's best values.
Labour's first term in power was hampered by spin and a "control
Now the second term had been dogged by "the centralisation of
power into the hands of the prime minister and an increasingly small number of
In the first government reaction to the speech, Defence Secretary Geoff Hoon said: "I simply do not recognise that description of the government in which I serve."
Number 10 denial
Earlier, Downing Street said Ms Short's five minute phone call to Mr Blair had been "perfectly cordial".
The prime minister's official spokesman even paid tribute to Ms Short for helping to make her department one of the "finest if not the finest aid departments in the world".
The speed with which Baroness Amos has been appointed to succeed Ms Short suggests her departure was no surprise to Number 10.
Baroness Amos becomes the UK's first black woman cabinet minister and - unusually for a departmental head - will tackle her brief from the House of Lords.
Conservative leader Iain Duncan Smith said Ms Short's departure underlined divisions which were damaging UK interests.
He said: "I think this demonstrates what we are seeing over the last few
weeks, the government is split from top to bottom on the euro, foundation hospitals, and Iraq."
Liberal Democrat Treasury spokesman Matthew Taylor said it was sad to see such a "doughty campaigner" for international development go.