European Commission head Jean-Claude Juncker has warned again that Britain must first agree its divorce terms with the European Union before any discussion of post-Brexit ties can begin.
"It has to be ultra clear that we will not begin any negotiation on the future relationship ... before all the separation issues are settled, that is the divorce of the UK from the European Union," Mr Juncker said.
Mr Juncker, a life-long proponent of closer EU integration, told an audience of EU diplomats that he was disappointed by the British government's approach to the Brexit negotiations.
"I have read with all necessary attention all the position papers drawn up by the UK government but none of them really give me satisfaction, so there is an enormous amount of questions that need to be resolved," he said.
Mr Juncker's comments came as the two sides continue a third round of Brexit negotiations in Brussels, which got off to a rocky start yesterday.
Chief EU negotiator Michel Barnier bluntly told his British counterpart David Davis as they went into the talks that Britain had to start "negotiating seriously," with a March 2019 deadline looming fast.
For his part, Mr Davis said the British position papers were "products of the hard work and detailed thinking that has been going on behind the scenes not just the last few weeks but the last 12 months".
"They should form the basis of what I hope will be a constructive week of talks between the European Commission and the UK," he said.
Progress would depend on "flexibility and imagination," he added.
The EU says there has to be "sufficient progress" in three key areas; EU citizen rights, Northern Ireland's border, and the exit bill, before considering the UK’s demand to talk about post-Brexit arrangements.
EU leaders are due to decide in October whether that has been achieved but there has been growing speculation the decision will be put pack to December as the gulf between the two sides shows no sign of narrowing.
