In his opening argument calling for a war crimes trial in Britain, Michael Mansfield QC said that the offence of waging an aggressive war has effectively been assimilated into English law.
The attempt to bring Blair – with the former foreign secretary Jack Straw and the former attorney general Lord Goldsmith – to court has been launched by the former Iraqi general Abdulwaheed al-Rabbat.
Rabbat, said Mansfield, was motivated by last year’s publication of the report of the Chilcot inquiry into the 2003 Iraq war.
Mansfield summarised the report’s findings as: “Saddam Hussein did not pose an urgent threat to the UK, intelligence reporting about [Iraqi] weapons of mass destruction was presented with unwarranted certainty, that the war was unnecessary and that the UK undermined the authority of the UN security council.”
“Nothing could be more emphatic than these findings,” he said. “It was an unlawful war.”
Mansfield argued that when British prosecutors had opened their cases at the Nuremburg war crimes trials at the end of the second world war, they had acted as though the crime of aggression had already been assimilated into English law.
An initial application to launch the prosecution was dismissed at Westminster magistrates court on the grounds that Blair enjoys immunity and that the crime of aggression does not exist in English law.
The current attorney general, Jeremy Wright QC, has intervened in the case to argue that the crime does not exist in the statute book. “The crime of aggression is not known to English law,” James Eadie QC, for the attorney general, told the court.
A number of Iraqi supporters of Rabbat sat at the back of the court. Speaking before the hearing started, Sabah al-Mukhtar of the Arab Lawyers Network, said: “This is just looking at whether the first court was right in refusing to entertain the case.
“The magistrates’ court dismissed it on the grounds that Tony Blair had immunity and that the crime of aggression was not part of English law. Many think they were not correct on that.”
Rabbat, a former chief of staff of the Iraqi army, was not in court. He currently lives in the Omani capital, Muscat.
His lawyers said he has been able to bring the case in British courts because the UK previously occupied Iraq. Under the European Convention on Human Rights he is therefore deemed to have been within the jurisdiction at a relevant time.
The high court reserved its decision and allowed a further week for Rabbat’s lawyers to make additional specified submissions. If the judges do not dismiss the appeal, the issue of whether the crime of aggression exists in English law will be sent up to the supreme court to decide.