Though this is in many ways is a given-having done so badly in the 2017 election, where she lost her party's parliamentary majority, the prospect of another campaign led by May fills most Tory MPs with terror-it is being treated as a setback to her authority.
Speaking after the win, she said: 'This has been a long and challenging day, but at the end of it I'm pleased to have received the backing of my colleagues in tonight's ballot.
They have been largely unhappy with the Irish backstop proposal.
Mrs Foster, whose 10 MPs prop up the minority Conservative administration, said she told the PM that "we were not seeking assurances or promises, we wanted fundamental legal text changes".
May added: "That must start here in Westminster with politicians on all sides coming together to act in the national interest".
While Theresa May, may stay, the time of her life is gone as Brexit seems not good enough for anyone. Before the no confidence vote Jeremy Corbyn was under pressure to call one of his own in the House of Commons, with SNP, Plaid Cymru, Lib Dems and centrist Labour MPs pushing for a vote.
Under Conservative Party rules, May can not be challenged as Conservative leader for another year.
When does she need to bring a new deal back to the House of Commons?
Sparked by anger that the Brexit deal she had negotiated was nothing like what voters had been promised, the dissenting MPs used the party rule book to trigger a vote of no confidence.
"There are 117 MPs in her own party that have said that they don't have confidence in her - how many of those can she convert to vote for her deal?"
Under such a scenario we would expect Sterling to consolidate the recent gain made in the wake of Theresa May's confidence vote win.
Theresa May to ask European leaders for help with Brexit
The six-point European Union document said any assurances would not "change or contradict" the legally-binding withdrawal agreement struck last month after two years of negotiations. "She will not be leading the Conservative Party into the next election".
Many supporters of Brexit say May's deal, a compromise that retains close economic ties with the European Union, fails to deliver on the clean break with the bloc that they want.Former Environment Secretary Owen Paterson accused May of acting like a "supplicant" in dealings with the EU.
"The result of the ballot held this evening is that the parliamentary party does have Conservative Party does have confidence in Theresa May as leader of the Conservative Party", announced Graham Brady, the Chairman of the Conservative Party's 1922 Committee.
Theresa May has gone back to Brussels to tell fellow leaders the United Kingdom wants a legal assurance concerning the controversial backstop clause held in the Withdrawal Agreement.
Sky News' Europe correspondent Mark Stone said: "This is a very interesting development".
She will remain leader, and prime minister, until the successor is picked.
May took over after her predecessor David Cameron quit following the shock vote for Brexit in June 2016, winning by default after her rivals fought among themselves or withdrew.
Brexiteer Jacob Rees-Mogg told the Press Association Mrs May should resign 'as soon as the Queen has a moment in her diary to see her'.
The EU leaders will then consider what could be done - without May in the room.
Faced with an apparently unassailable poll lead, she called a snap election in June 2017 to bolster her position and Brexit plan - only to lose the Conservatives' majority in the Commons.
According to the BBC's Brussels Correspondent Adam Fleming, "EU leaders are considering a commitment to continue negotiating a trade deal with the United Kingdom even if the Irish backstop comes into force - to prove that they want it to be temporary".
Chelsea launch investigation into racist abuse aimed at Sterling
Chelsea and the police are investigating the incident at Stamford Bridge on Saturday, which was highlighted on social media. Wing has since lost his job and is one of four Chelsea supporters to have been suspended by the club .