Theresa May has made a passionate plea to MPs to back her deal because "no-one knows what will happen" if they reject it, she said in a speech in Grimsby.
Addressing an audience of wind turbine workers, the Prime Minister said if MPs vote against her deal, "the only certainty would be on-going uncertainty".
Mrs May said discussions with the EU had been "at times difficult and robust" but both sides had worked to get a good deal over the line.
"Brexit does not belong to MPs in Parliament, it belongs to the whole country," she added.
The result of the 2016 referendum was "close but clear", but "the decision was to leave and that's what we must do," she said.
Theresa May's Brexit speech in Grimsby
The PM has pleaded with European Union leaders to give ground in order to help her Brexit deal survive next week’s Commons showdown.
She added: "Everyone now wants to get it done, move beyond the arguments, past the bitterness of the debate and out of the EU as a united country ready to make a success of the future."
Mrs May said: "Just as MPs will face a big choice next week, the EU has to make a choice too."
Her message to European Leaders, she said is: "This is the moment, this is the time, the British public have moved on, it takes both sides to get this negotiation through and bring it back to Parliament on Tuesday."
The prime minister's call for action from the EU came as Cabinet minister Liam Fox warned that Brexit might not happen at all unless MPs get behind the deal.
Mrs May said concerns for workers' rights after Brexit should be allayed by her promise to allow Parliament to vote on whether to adopt any new protections proposed by the EU.
"Leaving with a deal will mean workers are protected," she said. "And if they back the Brexit deal on Tuesday, MPs will give our whole economy a boost."
In spite of the "unavoidable uncertainty" of the Brexit process, Mrs May said the UK economy was doing well.
"Just imagine how much more we could achieve with the certainty of a deal," she said.
MPs will vote on Tuesday on whether to back the Withdrawal Agreement as Mrs May seeks further concessions on the Northern Ireland backstop in order to reverse the humiliating 230-vote defeat suffered the last time the Commons passed judgment on her Brexit deal.
In practical terms the Government needs an agreement by Sunday night at the latest as any new documentation relating to the deal must be published by Monday - the day before the vote.
Mr Cox and Brexit Secretary Stephen Barclay returned to Brussels on Friday in a final bid to secure an agreement ahead of next week’s crunch vote.
The EU said technical discussions are ongoing and insisted Brussels has already come forward with ideas to resolve the deadlock.
Mr Barnier said: "We are not interested in the blame game, we are interested in the result.
"We are still working."
After briefing EU ambassadors, Mr Barnier said in a tweet that the UK would not be "forced into customs union against its will" - but indicated that could result in the split between Northern Ireland and the rest of the UK that Mrs May had previously said was unacceptable.
He said the EU "commits to give UK the option to exit the Single Customs Territory unilaterally, while the other elements of the backstop must be maintained to avoid a hard border".
In further tweets Mr Barnier said the proposals included could include "good faith/best endeavours" to ensure the UK is not locked into the backstop post-Brexit, and most importantly, if the UK unilaterally exited the customs union before other ways had been found to keep open the border on the island of Ireland, Northern Ireland would stay in the customs union.
Great Britain would leave the customs union, but Northern Ireland would remain in it.
Meanwhile, Irish premier Leo Varadkar said the UK Government had failed to offer any solutions on the Withdrawal Agreement.
Speaking in Dublin, he said the deal reached in November, including the Irish backstop, was "already a compromise" delivered in response to British requests.
"We were and remain happy to apply the backstop only to Northern Ireland if they want to go back to that, it doesn't have to trap or keep all of Great Britain in the single customs territory at all or for a long period," said Mr Varadkar.
Number 10 is believed to hope a deal can be reached by Sunday night, with the possibility of the Prime Minister travelling to Brussels on Monday morning to meet Mr Juncker.
Ministers were said to be braced for another heavy defeat on Tuesday after the previous "meaningful vote" was lost by a majority of 230, with many MPs deeply unhappy about the backstop.