Rebel Labour MP Clare Short has resigned from the party and will sit as an independent for the remainder of this parliament, her office has confirmed.

The ex-Cabinet member has already said she will quit at the next election.

In her resignation letter she accused Tony Blair of "half-truths and deceits to get us to war in Iraq".

Earlier this month Ms Short was formally reprimanded by Labour for saying she will campaign for a hung parliament.

Labour Chief whip Jacqui Smith said she had breached the Parliamentary Labour Party's code of conduct.

But the former international development secretary escaped expulsion from the party over the remarks.

The Birmingham Ladywood MP has been a vocal critic of Mr Blair's foreign policy and leadership style since quitting the Cabinet in 2003.

In a resignation letter to the chief whip, Ms Short says: "It is my view that our political system is in trouble and that the exaggerated majorities in the House of Commons have led to an abject parliament and a concentration of power in Number 10 that has produced arrogant, error-prone government."

Previous resignations Ms Short has resigned from Labour's front bench on three occasions - twice over the Gulf Wars and once over prevention of terrorism laws.

Her 2003 resignation was seen as damaging her standing with Labour's left.

Rather than quitting before the conflict, like Cabinet colleague Robin Cook, she publicly agonised over its rights and wrongs.

She only left her post as international development secretary once the main hostilities ended.