Šefčovič stressed that he was hoping the UK and the EU could still make ‘decisive progress this week’ on the issue of medicines trade between Great Britain and Northern Ireland, which would ‘generate positive momentum’ for the rest of the talks.

Medicines are a pressing issue as a grace period for border checks and regulatory approvals for drugs expires at the end of the year. Although the U.K. decided to unilaterally extend that grace period, there is a risk of uncertainty and trade disturbance for medicines if both sides don't reach a deal before the end of January.

However, Šefčovič warned that the de facto deadline for reaching a deal was actually this week because the EU will need a few weeks to implement any potential solution.

He said the Commission would "most probably" have to launch the necessary internal approval procedures by next week, suggesting that the window of opportunity for striking a medicines deal was likely closing this week.