LONDON, March 17 (IslamOnline.net & News Agencies) - Protesting British Premier Tony Blair’s decision to go to war without UN approval, former British Foreign Secretary Robin Cook resigned from the British government Monday, March 17.

Cook's widely touted resignation came shortly after Britain's Ambassador to the United Nations Jeremy Greenstock had announced that diplomatic routes to resolve the crisis had been closed, according to Agence France Presse (AFP).

"It is with regret I have today resigned from the cabinet,” Cook, who saw Blair before the meeting, said.

"I can't accept collective responsibility for the decision to commit Britain now to military action in Iraq without international agreement or domestic support."

Cook is the first ministerial exit over Iraq policy, and a major blow to Tony Blair as he faces a growing rebellion within his own party over his handling of the crisis.

There is speculation that International Development Secretary Clare Short, who has already threatened to resign, may follow Cook onto the back benches Monday, AFP reported.

Cook’s resignation comes as the UK, U.S. and Spain effectively abandoned efforts to find a diplomatic solution to the Iraq crisis.

Cook has been appointed Leader of the House of Commons, the lower house of parliament, after he was removed from the foreign secretary's post in 2001.

"It is 20 years ago that I first joined Labor's shadow cabinet. It is with regret I have today resigned from its cabinet," Cook said in a statement.

"Cook will be making a personal statement this evening to the House of Commons and we will issue the correspondence (with the Prime Minister) shortly," according to AFP.

Meanwhile, British Cabinet Ministers are discussing holding a new vote in Parliament on the Iraq crisis Tuesday.

According to BBC News Online, former cabinet minister Chris Smith called Cook's resignation a "very honorable thing" to have done.

“He is a very senior, formidable, weighty figure and he will be a great loss to the government."

The move did not surprise Liberal Democrat foreign affairs spokesman Menzies Campbell.

"It was always likely that Robin Cook, who sought to introduce an ethical dimension into foreign policy, would find the ambiguity of the government's position too much to tolerate," said Campbell.

Conservative shadow foreign secretary Michael Ancram pressed Blair to ensure his cabinet spoke with one voice.

"While we understand Robin Cook's reasons for resigning, disunity within the cabinet is a matter of concern at this time," said Mr Ancram.

As war looms large, the Foreign Office advised all Britons in Kuwait, except diplomatic staff, to leave the country. The U.S. has also advised UN weapons inspectors to leave Iraq.

The legal case for war has been set out by the Attorney General, Lord Goldsmith, in a written statement in the House of Lords, according to the BBC.

Legal authority for war came from three previous UN resolutions - including one passed soon after the Gulf War in 1991 and the latest resolution, agreed last November, he claimed.

In an effort to win over skeptics, ministers are repeating assurances about the security of Iraq's oil reserves and efforts to resolve the Palestinian crisis.

More Labor MPs than the 122 who voted against the government last time are expected to rebel this time.

Ex-Labor whip Graham Allen and a group of MPs, including former cabinet minister Chris Smith, are drawing up the amendment.