Clare Short is to be given a formal warning about her conduct and told she may lose Labour membership for her scathing public criticism of Prime Minister Tony Blair.

The threat follows her most recent claim that the British government put pressure on its top legal official to give a licence to wage war on Iraq.

Chief whip meeting

The former secretary of state for international development will also be asked by the Government's "chief whip" Hilary Armstrong to explain why she went public on her bugging-the-UN claim.

Armstrong added that she had been sent more complaints about Short than about George Galloway – the last Labour Party member to be expelled after describing Blair and US President George Bush as "wolves".

Speaking after a Labour Party meeting, Kevin Barron and eight other MPs agreed Short should be "kicked out of the party".

The ex-minister did not attend and no one spoke in her defence.

No martyr policy

Blair has also discussed Short's future with the Parliamentary Committee, where backbench leaders raised their concerns with ministers.

The Parliamentary Labour Party's options include issuing a "yellow card" warning about her conduct; a formal reprimand and suspending or withdrawing the whip.

A warning is most likely because the Prime Minister believes a tougher response might provoke further embarrassing revelations from Short and could turn her into a martyr.