LONDON — Britain’s High Court on Monday blocked a bid by Saddam Hussein’s former chief-of-staff to prosecute former Prime Minister Tony Blair for invading Iraq in 2003.

Former Gen. Abdulwaheed Shannan Al Rabbat also sought to prosecute Blair’s Foreign Secretary Jack Straw and Attorney General Peter Goldsmith because of their involvement in the decision.

The case centered on the concept that a “crime of aggression” would be recognized under English law, as it is under international law. Al Rabbat’s lawyers argued that this would have made it possible for the British leaders to be held personally accountable — and subject to criminal trials and even prison — if convicted for their actions.

It is not the first time the British leadership has been called to account for the war in which the United States and Britain led a coalition to oust Saddam on the grounds that he held weapons of mass destruction. Other court action failed.

However, an inquiry into the Iraq war, led by John Chilcot, concluded that “the invasion was not prompted by the aggression of another country.”

The inquiry’s conclusion prompted Al Rabat’s lawyers to question earlier court decisions and to ask the Supreme Court to review the matter. But the judges rejected that bid, saying it was “for Parliament and Parliament alone” to decide whether “to make such conduct criminal under domestic law.”

Al Rabbat’s lawyer, Imran Khan, said Monday that the judgment “sets a dangerous precedent in times of global insecurity” adding that “any leader can act as he/she chooses knowing that whatever action they take, it can be taken with complete impunity.”

Khan called on Parliament to enact a law making accountability clear in the future.