A recently published biography of the late Princess Margaret claims the Provisional IRA had devised an assassination with a hitman named “The Jackal”.

"Princess Margaret: A Life of Contrasts" by Christopher Warwick, alleges that the IRA were infuriated by a comment that Princess Margaret made in October 1979.

At the time, the Queen’s sister reportedly told Chicago City Mayor Jane Byrne, “The Irish, they’re pigs.”

She was referring to the IRA’s assassination of her cousin Lord Mountbatten and his friends, who were killed on a fishing trip two months previously. 

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Her comments were widely circulated in the press, prompting outrage among the Irish and Irish American communities.

Her spokesman at the time, Lord Nigel Napier, vehemently denied that she had used these derogatory words. Mayor Byrne also insisted that the Princess was misquoted by the press.

Irish Americans staged protests for the remainder of the royal’s tour of the US. According to Warwick, US law enforcement was also adamant that the IRA had hatched a plan to kill Princess Margaret

“According to intelligence received from London, an IRA plot to assassinate Princess Margaret had been uncovered,” he wrote.

Security for Princess Margaret was heightened as she continued her US tour towards Los Angeles. The number of secret service agents attending alongside her was also doubled and a bulletproof armour added to her limousine.

FBI and British police were instructed to be vigilant for a suspected IRA assassin nicknamed "The Jackal".

On October 24th 1979, the Los Angeles Police Department raided a motel room they believed the gunman to be staying in but it was empty.

No attempt on her life was ever executed, and she arrived back in the UK days later.

Princess Margaret died some twenty five years later in 2002, aged 71. From natural causes.