LONDON (Reuters) - A group of lawyers aims to prosecute Prime Minister Tony Blair for war crimes at the new International Criminal Court (ICC) if an Iraqi war goes ahead.
They said national leaders could be held individually responsible for war crimes and be tried as ex-Yugoslav President Slobodan Milosevic has at a separate court for former Yugoslavia.
"There is a 100 percent certainty that Blair will be investigated by the ICC for war crimes if he attacks Iraq," said Phil Shiner of the Public Interest Lawyers firm in Birmingham.
He is leading a campaign to prosecute leaders in the seven-month-old ICC if military action goes ahead without a second United Nations resolution expressly authorising force, or if any Iraqi civilians are killed in bombing campaigns.
"The ICC brings a new international context to war -- Blair now has to consider his individual accountability," Shiner said.
The United States fiercely opposes the ICC, saying it would infringe U.S. sovereignty, but Britain has ratified its treaty and would have to give up any citizen the court wanted to try.
Nicholas Grief of Bournemouth University, who specialises in international law, said November's U.N. Security Council Resolution 1441 on Iraq did not authorise the use of force.
He said the resolution used the term "serious consequences" if Iraq did not comply with weapons inspectors, and not "use all necessary means", which has previously been used as a diplomatic code for authorising military force.
But former British government lawyer Tony Aust said the U.N. was deliberately obscure in its language.
"The U.N. is a prudish delicate flower -- it does not like to call a spade a spade, so never uses the word force," he said.
Grief and Aust debated the issue on a BBC radio programme on which Oxford University professor of law Vaughan Lowe said an Iraqi war would be illegal under international law.
The ICC's establishment has put the spotlight on individual responsibility for war's consequences and civilian casualties.
"The ICC will now place a serious constraint on Blair," Shiner told Reuters.
The court's independent prosecutor can initiate proceedings at the request of a state or can receive evidence from anyone, and then decide whether to prosecute, subject to advice from three of the court's 18 judges.
Grief said Blair could be tried for war crimes even in a U.N.-backed war, if there were a grave breach of the Geneva Conventions, ratified by Britain in 1957. If convicted, punishment could be life imprisonment.
Possible breaches include using weapons that are indiscriminate by nature such as nuclear weapons, or launching an attack that resulted in a clearly excessive loss of life or damage to the natural environment.
A government spokesman said any British involvement in armed conflict would be in accordance with international law.
