The government’s top law officer is going to court to demand the rejection of an attempt to prosecute Tony Blair over the Iraq war, the Guardian has learned.

The planned intervention by the attorney general comes after a judge ruled the former Labour prime minister had immunity from the attempt to bring a criminal charge against him and that pursuing a prosecution could “involve details being disclosed under the Official Secrets Act”.

The private prosecution relates to the 2003 Iraq war and seeks the trial in a British court of then prime minister Tony Blair, the foreign secretary Jack Straw, and Lord Goldsmith, the attorney general at the time.

It seeks their conviction for the crime of “aggression” and is based on the damning findings of last year’s Chilcot report into the British decision to join the invasion of Iraq, under the false pretext that the Saddam Hussein regime had weapons of mass destruction.

Legal documents seen by the Guardian show the attorney general, Jeremy Wright QC, who is the Tory MP for Kenilworth and Southam, has formally asked to join future hearings and for the attempt to prosecute Blair and his top aides to be rejected.

In November 2016, a court ruled the prosecution could not go ahead. But lawyers behind the private prosecution are seeking a fresh hearing to challenge that refusal and access to legal aid funding. The attorney general’s intervention is supported by the three Labour former senior ministers.

The attorney general claims the case is hopeless, in part because the crime of aggression does not exist in English law, even though it does exist in international law. But that argument appears to be undermined in a document written by Goldsmith himself.

UK attorney general Jeremy Wright says the basis of the claim for judicial review is ‘hopeless’. Photograph: Reuters

In his 2003 memo on the legality of the Iraq war, Goldsmith, then attorney general, appeared to concede the key point of those now seeking his prosecution. “Aggression is a crime under customary international law which automatically forms part of domestic law,” he wrote.

After the Chilcot report publication, some families of British service personnel who died in the war called for Blair to face criminal charges.

The latest attempt at a private prosecution comes in the name of Gen Abdul-Wahid Shannan ar-Ribat, former chief of staff of the Iraqi army and now living in exile, according to legal papers.

An application was made to Westminster magistrates court late last year for a summons to be issued against Blair but it was refused. The district judge, Michael Snow,said: “Implied immunity as former head of state and government ministers, therefore offence not made out … Allegations involve potential details being disclosed under the Official Secrets Act for which attorney general and director of public prosecutions consent are required.”

The lawyers behind the private prosecution attempt include Michael Mansfield QC and Imran Khan, who both battled for decades for justice on behalf of the family of Stephen Lawrence.

In their pleadings, the lawyers say: “If ever there was a case which required the actions of public officials to account for their alleged criminality, we cannot conceive of any better one than this. There is no doubt that there is significant public interest in these present proceedings and there should have been the concomitant application of the law to all decisions relating to it by the district judge. It would appear that there was not.”

They claim the judge was wrong to say because Blair was prime minister he and the former senior ministers cannot face prosecution: “It should be noted that, in any event, Tony Blair et al do not enjoy immunity from prosecution in the UK whether ‘implied’ or not.”

The lawyers add: “There are overwhelming grounds to challenge the decision of district judge Snow in refusing to issue the summons and it is highly likely that the administrative court will quash the decision … We would assess a greater than 80% chance of success as district judge Snow has made glaring errors of law.”



A spokesperson for Wright said: “It’s not unusual for the attorney general to intervene in cases in order to represent the public interest. He has sought to intervene in this case because it raises important issues about the scope of the criminal law.”

In his pleadings, the attorney general says he does not want courts making criminal laws, rather than parliament and “the basis on which this claim for judicial review is mounted is hopeless”, adding: “It is established by clear and unanimous authority at the highest level, the crime of aggression is not known to English law”. In a previous case, the law lords backed this view.

Wright says it is for parliament to decide what will count as a criminal offence under English law, and not the courts nor ministers.

The attorney general says he reserves the right to make other arguments as to why the attempted private prosecution should be stopped. In his arguments sent to the court so far, he does not make any comment on the assertion of his predecessor, Goldsmith, in 2003 that the crime of aggression exists under English law, nor whether Snow was correct in saying the former prime minister had implied immunity and thus could not be prosecuted.

Khan said: “My client wants those responsible held to account and prosecuted using the full force of the law. He is baffled as to why it is that despite the Chilcot report making it very clear that the war was illegal, attempts are now being made to prevent those responsible from entering a court, let alone being prosecuted for what they did.

“Everybody, including the attorney general should welcome this court case. It is an opportunity for many millions of people to get justice for something which caused immeasurable damage not just to the people of Iraq but all those others that were affected by these events around the world.”

Through a spokesperson, Snow declined comment.