A former IRA commander has boasted that he was behind the assassination of King Charles’s beloved great-uncle Lord Mountbatten.

Michael Hayes claims he designed the deadly explosive device and masterminded the plot to kill the war hero.

Mountbatten was murdered aged 79 when the IRA blew up his pleasure boat, Shadow V, at his summer home on the west coast of Ireland in 1979.

Hayes said he did not regret killing Mountbatten while describing the teenage boys, 14 and 15, who died as “casualties of war”.

He added: “I blew up Earl Mountbatten in Sligo, but I had a justification. “He came to my country and murdered my people.”

Legal experts say Hayes’s admission makes him liable for prosecution for murder, if the Irish authorities pursue him.