Tony Blair may face formal charges over war crimes if judges overturn a controversial ruling that gave the former Primer Prime Minister, immunity from prosecution over the Iraq War.

Last year a British court blocked a private criminal prosecution against Blair by General Abdul-Wahid Shannan ar-Ribat, a former chief of staff of the Iraqi army. British judges, however ruled that the international crime of “aggression” could not be brought against Blair and granted him immunity from criminal charges.

That ruling is set to be reviewed at the Royal Courts of Justice today by one of the most senior judges in the UK. In calling for a war crimes trial in Britain and the prosecution of Blair, Michael Mansfield QC was reported by the Guardian of saying that “the offence of waging an aggressive war has effectively been assimilated into English law”.

Read: The Chilcot Report explained

If the immunity verdict is overturned, Tony Blair may face formal charges of war crimes over one of the worst foreign policy disasters in British history. It would also satisfy large number of campaigners who hold Blair and the US President at the time of the Iraq invasion, George Bush, personally responsible for the death of hundreds of thousands of Iraqi’s and the rise of terrorism in the region.

This opinion gained further momentum following the publication of the Chilcot report which accused the UK of aggression following Blair’s decision to invade Iraq and depose Saddam Hussain over allegations of weapons of mass destruction. Chilcot inquiry’s also concluded that the invasion of Iraq was unnecessary and undermined the United Nations.