Hitting out at British Prime Minister Theresa May will form a government supported by a small Northern Irish party after her Conservative Party lost its parliamentary majority in an election debacle days before talks on Britain's European Union departure are due to begin.
As rumours swirled about plots to oust May, Johnson denied he was planning a leadership challenge.
"I am backing Theresa May. Let's get on with the job".
The Labour Party, led by Jeremy Corbyn, had been tipped to be decimated, but with a relatively high turnout at the polls boosted by younger voters, Labour made a significant recovery, picking up 31 seats to take 261 and well over 40% of the nationwide vote.
The timing is challenging, with Britain due to start negotiating the terms of its exit from the European Union with the bloc's 27 other members on June 19.
By early afternoon all but one of the 650 seats had declared, with the Conservatives on 318, well short of the 326 they needed for an overall majority. The main opposition Labour Party took 262.
Former Treasury chief George Osborne - who was sacked by May a year ago - called May a "dead woman walking", and opposition leader Jeremy Corbyn said he was ready to contest another election at any time.
Ahead of the election, Corbyn offered United Kingdom voters the most left-wing, big government policy agenda for almost 40 years - and crucially an end to seven years of Conservative "austerity" policies and campaigning on promises to push for better funding for health and education.
Their 2015 campaign was built around the hope there would be a hung parliament so that they would have more influence in the House - but David Cameron's majority meant that was not possible. Nick Clegg, the party's former leader who was Deputy Prime Minister under the 2010 coalition with the Conservatives, lost his seat, while the party leader, Tim Farron, held on with a narrow majority.
However, he acknowledged that the party would have to abandon much of the programme set out in the general election manifesto as it would no longer be able to get it through Westminster.
The Sunday Times reported that Chancellor Philip Hammond used a telephone call with Mrs May on Friday to tell her she should put jobs first in the Brexit negotiations - a coded attack on the immigration-focused strategy.
"The irony of this is that Theresa May is calling this a certainty government and talking about how it's delivering certainty", said Brian Klaas, a fellow in comparative politics at the London School of Economics.
After an initial round of discussions, Downing Street had said on Saturday that the "principles of an outline agreement" had been agreed with the DUP.
Davidson, who led her party to its best result for three decades, winning 13 seats in Scotland, said she had sought and received assurances from May on the issue.
Downing Street backtracked, saying she had "discussed finalizing" a deal in the coming week.
The two sides are looking to form a "confidence and supply" arrangement.
The DUP could agree to back the Government on the budget and any vote of confidence while deciding other measures on a vote-by-vote basis.
Ruth Davidson, the leader of the Scottish Conservatives, expressed those doubts publicly on Friday evening after speaking to May.
The DUP is opposed to abortion rights and same-sex marriage.
MPs will spend six days debating these plans before a vote on 27 June.
As MPs would vote with their conscience rather than along party lines, the lack of a government majority shouldn't be a factor.
Corbyn said Labour would try to amend the Queen's Speech to include its own commitments to end austerity and boost public spending.
After being elected unopposed past year, Foster told the Guardian: "I would not want abortion to be as freely available here as it is in England and don't support the extension of the 1967 act".