Prime Minister Boris Johnson's spokesman said on Tuesday that Britain wants to agree with the EU on simpler parts of the future deal.

"The EU continues to insist that we must agree on difficult areas in the negotiations such as EU state aid before any further work can be done in any other area of the negotiation, including on legal texts...We would instead like to settle the simplest issues first in order to build momentum in the talks as time is short for both sides" the spokesman said, as quoted by Reuters.

Earlier this week, French Foreign Minister Jean-Yves Le Drian addressed French ambassadors based in Europe alongside German counterpart Heiko Maas to say that the EU-UK post-Brexit trade talks have stalled "due to the intransigent and frankly unrealistic attitude of the United Kingdom."

EU chief negotiator Michel Barnier confirmed a lack of progress after the seventh round of trade talks which took place on 18 - 21 August.

The EU has been seeking a wide-ranging agreement in one comprehensive treaty, while the UK wants a simpler, "Canada-style" free-trade deal, with separate agreements reached on other issues. 

The sides mainly disagree over environmental and employment regulations, state-aid, fishing quotas in UK waters and a possible role for the European Court of Justice (ECJ) in overseeing the deal. London has repeatedly ruled out any jurisdiction for the ECJ over the UK's laws.

The UK held a referendum on leaving the EU in 2016 and officially left the bloc on 31 January, entering a transition period which is set to expire at the end of this year.