A British member of the Order of Malta, the chivalric organisation which dates back to the Crusades, has been suspended after writing a highly critical book about Pope Francis that was condemned as a “vile attack”.

Henry Sire, an Oxford-educated historian and a knight in the ancient order for nearly two decades, has been castigated for his inflammatory book The Dictator Pope, which describes the Argentinian pontiff as “authoritarian and manipulative”.

The book claims to be “the inside story of the most tyrannical and unprincipled papacy of modern times.”

"When the television cameras aren't rolling, Pope Francis transforms into another person: arrogant, stand-offish with people, vulgar in his language and famous for his violent outbursts of anger that are known to all, from cardinals to car drivers,” the historian wrote.

The book claims that Francis was elected thanks to the help of a “mafia” of progressive cardinals.

In a recent tweet, Mr Sire described the Pope as “the monster occupying the papal throne”.