July 24 (UPI) -- Boris Johnson said he's "convinced we can do a deal" on Brexit Wednesday in his first national address as British prime minister outside 10 Downing St. in London.
The new leader spoke after accepting Queen Elizabeth II's invitation to form a government.
Johnson said Britain will leave the European Union in October , "no ifs, no buts." He plans to get to work immediately on a deal.
"In the end, Brexit was a fundamental decision by the British people," he said. "I am convinced we can do a deal.
"It is of course vital at the same time that we prepare for the remote possibility that Brussels refuses any further to negotiate."
On his first day in office, Johnson began making key appointments and receiving government briefings. A number of moderate Conservatives on the Cabinet quit immediately after Johnson's installation as prime minister.
Johnson appointed Dominic Raab to two positions -- foreign secretary and first secretary of state -- what amounts to a role as deputy prime minister.
Among the other new appointees are Michael Gove, chancellor of the Duchy of Lancaster; Sajid Javid, chancellor of the exchequer; Andrea Leadsom, business, energy and industrial strategy minister; Priti Patel, home secretary; Elizabeth Truss, international trade secretary and president of the Board of Trade; Theresa Villiers, secretary of state for environment, food and rural affairs; and Gavin Williamson, secretary of state for education.
Those keeping their jobs are Brexit Secretary Stephen Barclay and Secretary of State for Health and Social Care Matt Hancock.
Johnson also appointed Dominic Cummings to be his senior adviser. Like Johnson, Cummings supports leaving the European Union and is a Conservative Leninist who's called for fundamental government reforms.
There are skeptics who fear leaving without a deal would be disastrous.
"At a time when increasing numbers of families have difficulties putting enough food on the table, we believe it is irresponsible to consider a course of action that is expected to make that situation worse," a statement by the Methodists, United Reform Church, Baptists, Church of Scotland, Salvation Army, Quakers and Scottish Episcopal Church said.
"I think as it stands today Boris Johnson could be the last prime minister of the United Kingdom," Westminster lawmaker Ian Blackford told BBC Radio.
Former leader Theresa May left Downing Street for the last time Wednesday before heading to Buckingham Palace to resign before the queen. She attended a final questioning Wednesday from lawmakers, who honored her and took a few shots at Johnson.
One opposition member asked how she feels handing over the country to a man who will "sell our country out to [U.S. President] Donald Trump and his friends."
May drew laughs when she said she was "pleased" to hand it over to Johnson after working with him in her Cabinet. Johnson quit the Cabinet because he felt May wasn't taking a hard enough stance on leaving the EU. May said she will "continue with my duties in the House, from the backbenches."
Opposition Labor leader Jeremy Corbyn asked May if she regrets any part of her fight against poverty and homelessness and called on her to oppose Johnson's "reckless plans."
May defended her record, saying she created jobs and allowed more people to go to college and buy a home.
Politics is "about the difference we make every day to the lives of people up and down this country," she said.