Officials say the lack of clarity from London on what Prime Minister Theresa May's government wants from the future relationship is making it impossible to craft a negotiating position that goes beyond generic points | Emmanuel Dunand/AFP via Getty Images Brexit deal at risk due to UK vagueness, says Brussels EU officials say the UK’s position on a future relationship is so unclear they cannot formulate a detailed negotiating position.

The U.K.'s position on a post-Brexit relationship with the Continent is so vague that it is preventing Brussels from drafting detailed negotiating guidelines for the final phase of talks, EU officials say — potentially endangering the chances of an eventual deal.

The officials say the lack of clarity from London on what Prime Minister Theresa May's government wants from the future relationship is making it impossible to craft a negotiating position that goes beyond generic points. That risks slowing down, or even delaying, talks on the future relationship, which are supposed to start in April.

Both sides are operating within a brutally tight timetable laid down in Article 50, so even a few weeks' delay would cast serious doubt on their ability to agree a final withdrawal agreement. Senior officials have said talks must be completed by October to leave time for ratification by the European and national parliament before the U.K.'s official March 29, 2019 departure date.

The warnings came a day after EU27 ministers, meeting at the General Affairs Council, issued their formal directives for negotiating a Brexit transition period amid signs that terms of the transition could be more contentious than expected. But the transition negotiation is expected to be far simpler than talks on the U.K.'s future relationship with the bloc — including a framework for future trade.

Producing a negotiating position would be far easier if the EU knew what its chief negotiator, Michel Barnier, will be presented with by his British counterparts across the table and there is increasing frustration at the U.K.'s unwillingness to clarify its position on key issues beyond a request for a "deep and special" future partnership.

"Basically everything we have so far is negative: no single market; no customs union; no [European Court of Justice]," a senior EU official said. "You know, all the red lines," the official said, adding: "We fear more and more that Theresa May and the Brits will not give us a good steer on the future relationship."

A senior EU diplomat from a Central European country said: “The risk is quite real that in March the U.K will not be ready to give us an unambiguous message.” The diplomat added, “That concern is also shared by others.”

Senior EU leaders, including German Chancellor Angela Merkel, French President Emmanuel Macron and Dutch Prime Minister Mark Rutte, have voiced exasperation over what they regard as a continuing lack of clarity from May and her government regarding Britain's specific objectives in the future relationship.

Merkel, in a speech at the World Economic Forum in Davos, said she was open to forging a new and close relationship with the U.K. but that the onus was on London to put forward its wishes. “It is in the hands of the United Kingdom to tell us how close a partnership it wants to have," Merkel said. "We are open to any form of partnership.”

There were similar calls for clarity from the EU side during Phase 1 of negotiations on the divorce issues — the Brexit bill, citizens' rights and Northern Ireland — but in that case it was the EU setting the agenda and it had clear priorities on all three. In Phase 2, many more issues are up for grabs.

British negotiators are used to the accusation that their proposals lack detail, and believe that the EU uses the claim to distract from their unhappiness with the U.K.’s proposals not to erect any new barriers to trade — an approach EU officials describe as "cake and eat it."

A U.K. government official, speaking on condition of anonymity, said: “From the beginning of this negotiation, the EU side has used the accusation of ‘lack of detail’ as a smokescreen for the fact that they don’t like some of the detail they are getting.”

May's government has come also under fire for lacking a clear Brexit position from members of her own party. During a debate Tuesday on the EU (Withdrawal) Bill in the House of Lords, former Brexit Minister Lord James Bridges said: "What do we value more, parliamentary sovereignty and control, or market access and trade? Four months on and there are still no clear answers to these basic, critical questions."

"All we hear day after day are conflicting, confusing voices," he went one, "If this continues and ministers cannot agree among themselves on the future relationship the government wants, how can this prime minister possibly negotiate a clear, precise heads of terms of the future relationship with the EU?"

EU officials said it was possible the EU27 would come forward with negotiating guidelines in March based on their limited understanding so far of May's objectives, much of it based on a speech she gave in September in Florence. But they cautioned that this would make the talks far more difficult.

Even on the relatively simple matter of a transition period where both sides agree on the basic format, the U.K. has begun raising unexpected objections. EU officials said they were stunned to hear the U.K. negotiator, David Davis, demanding that the U.K. have a mechanism for objecting to any new EU rules adopted while it does not have institutional representation in Brussels. Previously, each side had predicted the transition terms would be easy to agree.

EU27 officials on Tuesday said that the U.K. would only harm itself by prolonging the transition talks.

"We need to have an unequivocal message from them on the transition period,” the Central European diplomat said. "It doesn’t help that they talk of an ‘implementation’ period, which could mean an existing, semi-permanent phase. They are playing with ambiguity. Their participation in committees would undermine things and any extension of the transition could only prolong the limbo.”

Charlie Cooper contributed reporting.