To help British Prime Minister Theresa May convince her lawmakers to back the Brexit treaty, senior officials in Brussels are reportedly preparing to issue “reassurances” ahead of next week’s vote in London.

EU sources told the Reuters news agency that there is a request they said May put to fellow EU leaders at a summit before the Christmas break (December 14) to commit to having a new UK-EU free trade treaty in place by the end of 2021. However, the European Union shows no sign of going beyond an existing aspiration to do that, not a hard promise.

The date is important as it could allow May to assure her own party and others that the unpopular “Irish backstop” in the treaty would not be triggered after a status-quo transition period ends some time by 2022.

As explained by Reuters, the backstop would bind Britain to follow EU rules to avoid a “hard” customs border across the island of Ireland unless a better way is agreed to do that by means of a new trade pact. Critics of May’s deal to smooth Britain’s passage out of the EU on March 29 say the backstop could leave Britain subject to EU rules indefinitely, long after it gives up any say over them.

EU officials familiar with the discussions said they saw little sign of any shift in the position of EU leaders last month, when they said the agreement could not be renegotiated and they would make no binding commitments that could be construed as altering it.

“We can provide reassurances,” one official said. “But whatever it might be will just reiterate the (summit) conclusions from last month.”

On January 7, the European Commission said leaders would not renegotiate the treaty and that Brussels is pressing on with planning for Britain to crash out of the Union without a deal.

“The deal that is on the table is the best and the only deal possible,” the European Commission’s chief spokesman Margaritis Schinas told reporters when asked about a phone conversation on Friday between May and Commission President Jean-Claude Juncker.

He also repeated that there were no talks planned between negotiators from the two sides as “negotiations are complete”.