Britain’s High Court has blocked an attempt by an Iraqi ex-general to prosecute former Prime Minister Tony Blair for invading Iraq in 2003.

General Abdulwaheed Shannan Al Rabbat’s case centred on the concept that a “crime of aggression” would be recognised under English law. But the High Court said that while the concept exists under international law, it does not exist in domestic law at present.

“Having formed the view that there is no prospect of the Supreme Court overturning the decision [by the lower court], it is our duty to refuse permission to bring the proceedings for judicial review,” it said.

The former army general’s lawyers said in a statement on Monday that the judgment “sets a dangerous precedent in times of global insecurity” and called on parliament to enact a law making accountability clear in the future.

The United States and Britain were part of a coalition that invaded Iraq in 2003, following accusations that Iraqi President Saddam Hussein held weapons of mass destruction.

Lawyers for Al Rabbat had argued that last year’s publication of the Chilcot Inquiry into the Iraq war had given new grounds to prosecute Blair.

The inquiry concluded that Blair’s government had decided to invade Iraq before exhausting peaceful options, used intelligence presented with a “certainty that was not justified”, and undermined the authority of the United Nations.

Following its publication, Blair admitted “mistakes in planning and process” but said he would take the same decision again.