On what many are coining "Brexit judgement day", UK Prime Minister Theresa May took questions from members of parliament.
Speaking to the parliament on Wednesday, May said that she will be delivering on Brexit and stressed: "We will not rerun the referendum".
"We will deliver Brexit and the United Kingdom is leaving the European Union on the 29th of March 2019," she added.
The UK Parliament speaker said he had been told there would be an official Brexit statement from the government on Thursday.
"I had been given to understand there would be a statement on this matter, in all likelihood tomorrow," Speaker John Bercow said.
A draft Brexit deal was finalised late Tuesday between EU and UK negotiators.
The Democratic Unionist Party (DUP) and prominent Brexiteers quickly criticised the 500-page document, with DUP leader Arlene Foster saying that she could not support a deal that would see Northern Ireland in a separate regulatory system than the rest of the UK.
"Our desire for a deal will not be suspended by a willingness to accept any deal," Foster said in a statement.
British MEP and architect of the Brexit referendum, Nigel Farage, called the agreement "the worst deal in history," while Labour leader Jeremy Corbyn said that "given the shambolic nature of the negotiations, this is unlikely to be a good deal for the country".
DUP, the Northern Irish party, props up May's government and had threatened before to vote down her UK budget proposal should a Northern Ireland border proposal not satisfy the party.
In recent months, the Northern Ireland border has become the key impasse to negotiations with the DUP and Brexiteers calling for Northern Ireland to remain within the same customs regulatory system as the rest of the UK post-Brexit.
To prevent a return to check-points and infrastructure along the Irish border, EU chief Brexit negotiator Michel Barnier had suggested that the border be established along the Irish Sea — a proposal that was strongly refuted by the DUP and Brexiteers.