Theresa May’s job, and her country’s departure from the European Union, have been decided for now after the British Prime Minister won a desperate bid to convince cabinet to back her draft Brexit agreement.

Ms May announced Thursday morning that cabinet had approved her much-criticised Brexit deal after a marathon, five hour meeting, describing it as “the best we could negotiate”.

The Prime Minister will address Parliament later Thursday, when she could face a possible vote of no confidence in her leadership instigated by Brexit supporters, according to BBC political editor Laura Kuenssberg, citing a senior member of Ms May’s Conservative Party.

Brexiteers were so angry with the draft Brexit deal they were submitting letters to the head of a committee of Conservative MPs responsible for handling any leadership challenge,” Ms Kuenssberg quoted the party member as saying.

“Senior Tory (Conservative) tells me Brexiteer anger so high that seems likely there will be a call for no-confidence vote tomorrow – letters going in,” she said on Twitter.

The draft Brexit deal had been widely denounced by both supporters and opponents of the European divorce.

Brexit campaigners in Ms May’s Conservative Party said her deal was a surrender to the EU and threatened to vote it down.

“This is firmly in the national interest and is a deal that delivers on the promise of the referendum,” Ms May said after the cabinet meeting.

“The decision protects jobs and the [European] Union,” she said.

“This is a decision that will come under intense scrutiny, but the decision was to build a future for our country or to go back to square one and fail on the promise of the referendum.”

As Ms May and her MP’s met late into the night, London time, reports on the BBC suggested a leadership challenge could be imminent.

The cabinet agreement is still just one step in a long fight for Brexit ahead of the formal departure in March, with the contentions deal still requiring a passage through the UK parliament.

The Northern Irish Democratic Unionist Party, which props up May’s government, said it would not back any deal that treated the British province differently from the rest of the UK.

Opposition Labour Party leader Jeremy Corbyn called it a “botched deal”.

Brexit-supporting Conservative members of parliament have made their unhappiness clear.

“If the media reports about the EU agreement are in any way accurate, you are not delivering the Brexit people voted for, and today you will lose the support of many Conservative MPs and millions of voters across the country,” MP Peter Bone said before the meeting.

Ms May, an initial opponent of Brexit who won the top job in the turmoil following the referendum, has staked her future on a deal which she hopes will solve the Brexit riddle: leaving the EU while preserving the closest possible ties.

The government gave no immediate details on the Brexit deal text, which runs to hundreds of pages, although a statement to parliament was likely on Thursday.

At the heart of conflict among UK politicians has been the so-called Northern Irish backstop, an insurance policy to avoid a return to controls between the British province and EU-member Ireland which could threaten the 1998 peace accord which ended 30 years of violence.

-with AAP