The Queen, who is at her home in Windsor Castle, held her weekly audience by telephone with Mr Johnson on Wednesday evening. He is said to have given her a courtesy call the following morning before announcing his decision to resign to the nation, although the palace would not confirm this.
Mr Johnson is resigning as the Conservative leader later on Thursday, following a slew of ministerial resignations this week. He plans to continue his role until the autumn to allow a Tory leadership contest to take place in the summer, despite some Tory MPs calling for him to step down immediately.
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Mr Johnson will have to travel to the Queen to officially tender his resignation, usually after his successor has been appointed. This resignation audience usually takes place at Buckingham Palace but given the Queen's age and mobility issues, and the timing of the leadership contest, if the sovereign is at her holiday home Balmoral over the summer, the audience could potentially take place in Scotland.
Mr Johnson is the Queen's 14th Prime Minister during her reign. The monarch is politically neutral and acts on the advice of her government in political matters.
Although Mr Johnson openly stated in his Parliamentary tribute to the Queen during her Jubilee year that his weekly meetings with the monarch were "immensely comforting, because she has seen the sweep of it".
Boris Johnson at the Queen's Platinum Jubilee celebrations in June
His tenure hasn't been without its controversy though. Mr Johnson broke protocol twice when he publicly spoke about the pair's private audiences, saying in November 2019 on the day Parliament was dissolved: "I'm just off to see Her Majesty the Queen, which is always a very tough interview because she always asks the best questions and the question today is: 'Why are we having this election?'"
His tenure hasn't been without its controversy
In July 2019, Mr Johnson also revealed what the Queen said when he took over from Theresa May. A correspondent for Euronews NBC said the politician claimed the monarch quipped, "I don't know why anyone would want the job."
Earlier this year, the Prime Minister also had to publicly apologise to the monarch and the country after holding two parties at No 10 Downing Street while the nation was mourning the passing of the Duke of Edinburgh.
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