The Attorney General is seeking to block a bid to prosecute Tony Blair over the Iraq war, according to reports.
Tory MP Jeremy Wright QC, the Government's top law officer, has formally asked to join hearings to oppose such a move against the former prime minister, The Guardian has said.
A spokeswoman for the Attorney General would not be drawn on 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."
The Guardian said the planned move by the Attorney General follows a ruling that Mr Blair had immunity from the attempt to bring a criminal charge against him on the issue, and that pursuing a prosecution could "involve details being disclosed under the Official Secrets Act".
The private prosecution is in relation to the 2003 invasion of Iraq and seeks the trial of Mr Blair, 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 into the war, according to The Guardian.
The newspaper said it had seen legal documents showing Mr Wright has formally asked to join future hearings and for the attempt to prosecute Blair and his top aides to be rejected.
The Attorney General claims the case is hopeless because the crime of aggression does not exist in English law, even though it does exist in international law, the newspaper said.
However, the newspaper quoted a 2003 memo from Lord Goldsmith stating: "Aggression is a crime under customary international law which automatically forms part of domestic law."
The Attorney General's spokeswoman told The Press Association: "It is not unusual for the Attorney General to intervene in these sort of cases in order to represent the public interest."