Mrs May will travel to Belgium for discussions with European Commission president Jean Claude-Juncker on Saturday before Sunday's special Brexit summit of EU leaders.
In a further twist for the Prime Minister on Friday, Spanish PM Pedro Sanchez was threatening to derail the talks over concerns about Gibraltar in her deal.
Mrs May has insisted a final agreement is "within our grasp". But even if the deal is rubber-stamped by the EU, she will face an uphill battle in Westminster to persuade MPs to back it.
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