The House of Commons will vote on the withdrawal agreement and the political declaration before Christmas, British Prime Minister Theresa May said on Sunday.

Speaking at a news conference in Brussels, May once again defended the deal reached with the EU and said it was the only deal available.

Earlier, the 27 members of the EU approved the withdrawal agreement and political declaration on the future EU-U.K. relations.

May said today was the culmination of a long and difficult process but start of a "crucial national debate" but she was "confident we have achieved the best deal."

"The public would expect parliament to vote on the deal. For most people in the U.K. they want a deal done and want us to get on with focusing more clearly on the issues that matter to them day to day," May said.

Parliament vote

A very turbulent period now lies before the members of the U.K.’s House of Commons, as they will vote on the deal in the coming weeks.

The vote has already been debated since the details of the Brexit deal was published last week by the British government. The opposition parties, Northern Ireland’s DUP and some members of May’s Conservative Party -- including the party’s former leader Ian Duncan Smith -- said they would not back the deal.

Labour Party leader Jeremy Corbyn said on Sunday his party will oppose May's Brexit deal in the parliament, describing it as a "miserable failure of negotiation that leaves us with the worst of all worlds."

“I am totally convinced that this is the only deal possible,” Jean-Claude Juncker on the other hand said.

“Those who think by rejecting the deal that they would have a better deal will be disappointed in the first seconds after the rejection of this deal,” he warned British MPs.

May will almost certainly face a domestic impasse back home as up to 40 Tory MPs signaled that they would trigger a vote of no confidence against her as they think she will not deliver a Brexit that people voted for.

They particularly are against the idea of leaving the country anchored to EU rules and laws without any say in the EU’s decision-making mechanisms.

May defends the deal

May said the deal will give the country "an immigration system based not on where people come from, but on skills and talents.”

It will also bring "an end to vast annual payments being sent to the EU,” and “to the jurisdiction of the European Court of Justice in the U.K," she said.

"The U.K. will be an independent coastal state once again, with full sovereign control of our waters," as it will be leaving the EU Common Agricultural and Common Fisheries policies completely, May added.

She also ruled out the possibility of a second referendum on the deal.