London (CNN)The United Kingdom and the European Union are closing in on a post-Brexit trade agreement after months of fraught negotiations, sources told CNN.

A deal is expected to be announced on Christmas Eve, a UK government source and a European diplomatic source told CNN. News of a potential deal was also reported by the UK’s PA Media news agency.
The announcement would come ahead of the December 31 deal deadline.
A senior source at No. 10 Downing Street told CNN that the UK cabinet was briefed on negotiations in a late-night call Wednesday. Following that briefing, the source told CNN: “Expecting talks over the legal text to last into the early hours.”
European Commission Chief spokesman Eric Mamer then hinted at final details being ironed out. At about midnight local time he tweeted: “#brexit work will continue through the night. Grabbing some sleep is recommended to all brexit-watchers at this point. It will hopefully be an early start tomorrow morning…”
Earlier on Wednesday, a No.10 adviser told CNN that talks were “moving but not there” yet. An EU diplomat agreed, telling CNN on Wednesday a deal could come “today or tomorrow but was not there yet.”
Talks have been deadlocked for months after the two sides were unable to reach agreement in areas such as fishing quotas, how the UK would use state aid to support British businesses post-Brexit, and legal oversight of any deal struck.
Any potential deal would subsequently face a ratification process before coming into effect on January 1, 2021, when the Brexit transition period ends and the UK will no longer be subject to EU rules.
There were once concerns that the deal would not be ratified before the transition period expired; however, European institutions, including the European Parliament, have agreed to sit extra hours towards the end of the year in order to get the agreement approved in time.
Fears of any holdups in the deal’s approval in time for the end of the transition period have been mostly allayed by the fact that it’s largely possible to provisionally implement trade deals before they are ratified, meaning that in a worst-case scenario, the most serious damage could still be avoided.
News of a potential agreement comes against the backdrop of surging coronavirus cases in the UK. Meanwhile, thousands of trucks from across Europe faced a third day stuck at the English port of Dover after the now-lifted closure of the border by France over a potentially more contagious variant — a preview of the type of border chaos that could have resulted from a “no deal” Brexit.
But the breakthrough marks a major milestone in the saga that began with the UK voting to leave the EU in 2016.