The Attorney General is looking to block a bid to prosecute former prime minister Tony Blair over the Iraq war, according to reports.

Tory MP Jeremy Wright QC, the government's top law officer, has formally requested to join hearings to oppose such a move against Mr Blair, the Guardian has said.

A spokeswoman for the Attorney General would not reveal whether Mr Wright would oppose the attempted prosecution, but told the Press Association: "He is seeking to intervene in this case because it raises issues about the scope of criminal law.

"It is not unusual for the Attorney General to intervene in these sort of cases in order to represent the public interest."

The newspaper said the planned move follows a ruling that Mr Blair had immunity from the attempt to bring a criminal charge against him, and that pursuing prosecution could "involve details being disclosed under the Official Secrets Act".

The private prosecution relates to the 2003 invasion of Iraq and seeks the trial of Mr Blair, along with then-foreign secretary Jack Straw, and the attorney general at the time, Lord Goldsmith, the newspaper reported.

It seeks their conviction for the crime of "aggression" and is based on the findings of the Chilcot report.

The Guardian said it had seen legal documents showing Mr Wright has asked to join future hearings, and for the attempt to prosecute Mr Blair to be rejected.

The Attorney General claims the case is futile because the crime of aggression does not exist in English law.