Negotiators from the UK and European Union (EU) have met face to face in an effort to make progress on a post-Brexit trade deal.

Teams led by the Prime Minister’s Europe adviser, David Frost, and the EU’s Michel Barnier held talks in Brussels for the first time since the coronavirus crisis forced them to be held remotely.

Mr Barnier said they would “make the most” of the intensified process over the coming weeks and months.

He said the EU remains “calm and united in its principles and values”.

Key stumbling blocks in the talks include the “level playing field”, aimed at preventing the UK lowering standards on workers’ rights, environmental protection and state subsidies.

The UK side has claimed the proposed measures would leave it tied to Brussels’ rules despite leaving the EU.

The meeting – held with participants spaced around the conference table due to social distancing measure – came a day after it was announced that Mr Frost would replace Sir Mark Sedwill as national security adviser alongside his responsibilities on Europe.

Downing Street indicated that it wanted a post-Brexit deal largely concluded by the time he takes up the new role at the end of August.

Boris Johnson has previously said he wants the UK-EU talks to result in a deal by the end of July, although both sides have acknowledged that the end of October is when an agreement needs to be concluded in order to ratify it this year.

The Prime Minister’s official spokesman said: “We have been clear on a number of occasions that these talks shouldn’t drag and that we want and need them to concluded by the autumn.”

The current transition period expires at the end of the year, meaning new arrangements will need to be in place by January 1 or the UK will follow World Trade Organisation rules for its relationship with the EU.

European Commission spokesman Daniel Ferrie said: “Our overall message this week, but also for the coming weeks and coming months, is to intensify our negotiations in order to make progress in order to get a deal.”

Mr Ferrie said he had “no particular comments to make” about Mr Frost being given a second job while the negotiations continue.

He added: “From our side at least we are fully concentrated on the negotiations.”

Ahead of the latest round of talks, Mr Frost said the EU’s “unrealistic positions” need to change if there is to be any progress.