In a 10,000 word dossier delivered to Lord Advocate Elish Angiolini, Mr Sillars submits that Tony Blair should be held to account for conspiring to overthrow Saddam Hussein's regime and for starting the war in Iraq, both contrary to international law.

A previous attempt to raise a similar action in England failed because lawyers argued that it was not the place to deal with international law.

But Sillars claims Scottish courts have the power to try Blair for war crimes if they believe an established offence, such as murder, has been committed in the process. He said he had been told by legal experts that the Prime Minister has a case to answer.

Sillars said: "There can be no prosecution at the international criminal court because it doesn't have jurisdiction.

"There is no chance of a special court being established by the United Nations because Britain and the United States have the veto at the Security Council. There is no chance of a prosecution in England and Wales.

"But of course Scots law is an entirely different entity, an entirely different jurisdiction with different rules, procedures and instruments available to it."

And he warned: "The Lord Advocate would have to give a very good explanation why, with the evidence presented, she didn't instigate an investigation, because we have jurisdiction."