Boris Johnson's father has likened Michael Gove to the assassins who murdered Julius Caesar.

Asked about Mr Gove's brutal attack which knocked his son out of the Tory leadership race, Stanley Johnson quoted Caesar's supposed last words after he was stabbed by his former friend Brutus.

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"'Et tu Brute' is my comment on that," he told BBC Radio 4's The World at One. "I don't think he is called Brutus, but you never know."

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Mr Johnson senior said Mr Gove's devastating denunciation of his ability to lead the country had taken his son by surprise.

"This has obviously been a very, very stressful time. I think he was probably very surprised by Michael Gove's sudden move as indeed many people are," he said.

Despite having backed the Remain campaign in the EU referendum, he praised his son's brilliant "career move" in putting himself at the head of Leave campaign.

"Boris's career move I think was in a sense an absolutely brilliant move in one way because it did put on the table crucial issues for the British electorate," he said.

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"It put on the table the immigration issue, the direction of travel issue, the sovereignty issue - all those things."