After almost a decade of making money by milking the contacts he had made as prime minister, Tony Blair recently made a surprise comeback to domestic politics.

He has created an institute to promote his own brand of ‘centre-ground’ politics, and has again become a familiar figure on the British scene.

I dare say that Mr Blair is hoping we will all forget that he led this country to war against Iraq — a calamity that is still unfolding today with the horrors of ISIS.

Tony Blair faces being taken to court in a private prosecution charging him with telling lies about Saddam Hussein's weapons of mass destruction to take Britain into an illegal war

However, that is a mistaken hope, because the former prime minister still has hugely serious questions to answer about his personal role.

Mr Blair faces being taken to court in a private prosecution charging him with telling lies about Saddam Hussein’s weapons of mass destruction in order to take Britain into an illegal war.

The litigants argue that Mr Blair is guilty of the crime of ‘aggression’ — or the illegal invasion of another country. This is the most serious crime anyone can commit under international law.

It was defined as such in the Nuremberg Military Tribunal into Nazi war crimes in 1946 when the chief prosecutor, Justice Robert H. Jackson, declared that the initiation of a war of aggression ‘is the supreme international crime differing only from other war crimes in that it contains within itself the accumulated evil of the whole’.

Charges

The case is being brought by the former chief of staff of Saddam Hussein’s army, General Abdul-Wahid Shannan ar-Ribat. He is seeking a judicial review of a district judge’s decision last November that Blair had ‘immunity’ from criminal prosecution.

Some years ago, one of our most eminent soldiers, General Sir Michael Rose, called for the impeachment of Blair

However, General ar-Ribat, who lives in exile, is by no means a vexatious litigant.

Many respected observers are convinced that he is absolutely right, and Mr Blair has serious charges to answer.

Some years ago, one of our most eminent soldiers, General Sir Michael Rose, called for the impeachment of Blair.

More recently, Hans Blix, chief weapons inspector for the UN before the Iraq invasion, told me Blair lied in order to take Britain into an illegal war.

The inspection team’s advice at the time was that it was likely Saddam Hussein had terminated his WMD programme some years before.

Last year’s Chilcot report, while hesitating to reach a judgment, raised serious questions about Blair’s conduct concerning the path to war.

Mr Blair, naturally, insists he acted in good faith based on the intelligence available to him at the time.

Notorious

Bear in mind it’s a fundamental principle of international law that states are prohibited from using force except in self-defence or unless its use is formally authorised by the Security Council under chapter VII of the UN Charter.

Sir John Chilcot demonstrated beyond doubt that the invasion of Iraq was not (as Blair notoriously claimed at the time) a war of self-defence against Iraqi aggression. Sir John also demonstrated that the war was not authorised by the UN Security Council.

The evidence that Tony Blair is a war criminal is therefore powerful and compelling. That being the case, the former prime minister ought to be brought to book.

That is why I am certain that General ar-Ribat is fully entitled to take legal action, and that he and Mr Blair must have their day in court.

And that is why yesterday’s story in the Mail that the most senior law officer in the British Government has intervened to request that the case should not go ahead is so profoundly concerning.

Sir John Chilcot demonstrated beyond doubt that the invasion of Iraq was not a war of self-defence against Iraqi aggression. He also found the war was not authorised by the UN Security Council

Jeremy Wright QC, the Attorney General — who was appointed by David Cameron — says the case is ‘hopeless’ because the crime of aggression does not exist in English law. His position has been backed by the law lords.

Yet this seems to be curiously at odds with a document written by the man who was Attorney General on the eve of the invasion of Iraq in 2003. In a famous memorandum on the legality of the invasion, Lord Goldsmith wrote: ‘Aggression is a crime under customary international law which automatically forms part of domestic law.’

To the casual observer, this new intervention to shield Mr Blair from legal scrutiny in court must seem extremely rum. It seems to hint at disturbing double standards at the heart of the British political system.

If the man in the street breaks a law, he should expect to be taken to court and, if found guilty, punished. So is there one rule for ex-premiers and their ministers, and another for the rest of us?

Jeremy Wright QC, the Attorney General, says the case is ‘hopeless’ because the crime of aggression does not exist in English law. His position has been backed by the law lords

Blair lied to Parliament to make the case for an illegal war that directly led to the deaths of 179 British soldiers and indirectly to the deaths of hundreds of thousands of Iraqis.

Some of the families of those British troops are seeking a civil action against Blair and other Whitehall officials for ‘misfeasance in public office’.

Barristers for the families have pored over last year’s Chilcot report and conclude there is a strong case that Mr Blair misled Parliament to justify the catastrophic war.

So, why has he never been held to account? And why has the Attorney General been so proactive in stopping this action by the Iraqi general against him?

It’s important to remember that this is not the first time Blair has seen the shadow of the law approaching his door.

Just over ten years ago, the Metropolitan Police presented a powerful dossier to the Crown Prosecution Service that they felt proved peerages were up for sale to Labour Party donors.

That investigation, to the bafflement and fury of the police, was to go no further once it reached the CPS.

In the wake of the damning Chilcot report, David Cameron refused to admit that the war was ‘a mistake’ or ‘wrong’

We also know that the British Government was complicit in torture during the Blair premiership as part of the U.S. ‘War on Terror’ (though, to be scrupulously fair to Mr Blair, we cannot say for certain whether he personally licensed this). The 1988 Criminal Justice Act states that carrying out or abetting torture is punishable by jail, with the maximum of life imprisonment. So the Met had no choice but to investigate, once evidence of wrongdoing emerged.

Once again it mounted a very thorough investigation. Once again, I understand the police presented a powerful dossier to the CPS. Once again the CPS failed to bring any charges against Blair or his ministers.

Much as those were both deeply serious matters, neither compares in scale or historic importance with the Blair government’s prosecution of the Iraq war.

Thus far, Mr Blair has not paid the slightest price for the disaster of Iraq, even though the Chilcot report could hardly have been clearer about the appalling lies he told about Saddam Hussein’s weapons of mass destruction.

What strikes me as odd is the way that two consecutive Conservative governments have failed to make Blair face sanction for his actions.

Shameful

Last year, in the wake of the damning Chilcot report, David Cameron refused to admit that the war was ‘a mistake’ or ‘wrong’. Now we have the Tory Attorney General stepping in to stop a legal action against the former Labour premier.

Cynics would say it’s almost as though there is a club of ex-PMs whose unwritten rules dictate that no prime minister should allow any of his or her predecessors to be prosecuted or held to account for fear that the same could in due course happen to them.

Time will tell us whether Mr Blair will ever stand in court and answer questions about the Iraq war. But the evidence seems clear enough to me.

Indeed, his lies remain to this day on the parliamentary record, in defiance of the ministerial code that says ministers must correct errors ‘at the first opportunity’.

More than that, the failure to prosecute Mr Blair means that he has been free to return to British politics and make the case for the European Union and what he calls the ‘centre ground’. What a shameful state of affairs.