BRUSSELS: The EU told Britain bluntly today that it had to get serious about the Brexit negotiations and address key separation issues first before any talks about its future relationship with the bloc.
The European Union says there has to be "sufficient progress" in three key areas -- EU citizen rights, Northern Ireland's border and the exit bill -- before it will turn to post-Brexit arrangements, possibly beginning in October.
Chief EU negotiator Michel Barnier initially exchanged pleasantries with his British counterpart David Davis but swiftly changed tone to demand London come up with detailed responses to Brussels' positions.
"To be honest, I am concerned, time passes quickly,"
Barnier told reporters ahead of a third round of Brexit talks in Brussels.
"We welcome the (recent) UK government papers and we have read them very carefully... but we must start negotiating seriously," he said.
"We need UK papers that are clear. The sooner we remove the ambiguity the sooner we will be in a position to discuss the future relationship and a transitional period."
For his part, Davis read a statement issued earlier today in which he said Britain had been working hard on its position papers.
Without replying directly to Barnier's comments, Davis said the British documents 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 will require "flexibility and imagination from both sides," he said, adding: "We're ready to roll up our sleeves and get down to work again once more."
London says the EU's insistence on the sequencing -- the divorce settlement then future trade and political ties -- may be counterproductive.
If the two strands were negotiated in parallel, it might actually help resolve other sticky issues such as the future EU-UK border between Northern Ireland and the Republic, it says.
Last week, EU officials rejected any such connection, downplaying expectations that a "very big gap" could be bridged by the time Barnier and Davis address the press again on Thursday.
Both sides have repeatedly warned that the clock is ticking down to the March 2019 Brexit deadline and that they are the ones doing their best to make progress.
The talks are taking place against a backdrop of deep political uncertainty in Britain, with the opposition Labour Party over the weekend backing a "soft" Brexit whereby the country remains in the EU's customs union and single market for a transition period.
Prime Minister Theresa May has said she wants Britain unequivocally out of both but her position has been crippled since a June election gamble backfired and she lost her parliamentary majority.
May remains in office thanks to a deal with Northern Ireland's ultra-conservative Democratic Unionist Party which views the Republic, an EU member, with deep suspicion.
EU officials warned last week that the hard-won Northern Ireland peace process could not be used as a bargaining chip.
London's hopeful suggestion that technology could help prevent the border becoming a physical barrier jeopardising the peace process was just "a lot of magical thinking", one EU official said.
In another position paper, Britain said the European Court of Justice could continue to have an indirect influence, softening its position that the EU's top court would not have any say in the country at all.
But again this is not enough, EU officials said.
The rights of more than three million EU citizens in Britain and one million Britons in Europe arose from EU law, and so remain the remit of the ECJ.
"There is no other possibility," one official said.
As for Britain's divorce settlement -- estimated at up to 100 billion euros in Brussels but much less at 40 billion according to reports in London -- EU officials said the talks were not about fixing a number but about agreeing how to work out the bill.
"We have to have a methodology sufficiently detailed so that commitments made to various beneficiaries of the EU budget will be honoured," one of the EU officials said.