Prime Minister, Theresa May, congratulated Boris Johnson, her successor, as Conservative party leader, and urged him to “work together to deliver a Brexit that works for the whole UK”.
May, who is due to hand over leadership of the country to Johnson on Wednesday, also urged him to ensure the Conservatives “keep (opposition Labour leader) Jeremy Corbyn out of government.”
“You will have my full support from the back benches (of parliament),” she added.
Johnson will not take office formally until Wednesday afternoon.
May will face her final prime minister’s questions in the House of Commons before tendering her resignation to the Queen.
Johnson will then go to Buckingham Palace himself for his appointment to be confirmed – before being driven to Downing Street to give a speech in front of the black door of No 10.
He takes charge at a perilous political moment.
The Conservatives’ wafer-thin parliamentary working majority is expected to be eroded further next week – to just two – if the Liberal Democrats win the Brecon and Radnorshire byelection.
Johnson has faced a furious internal revolt even before arriving in Downing Street, with several key cabinet ministers, including the chancellor, Philip Hammond, saying they will resign rather than serve under him.
They have been alarmed by Johnson’s insistence that he is willing to countenance leaving the European Union without a deal on October 31, rather than postpone Brexit once again – even if that meant proroguing parliament.