The European Union urged the United Kingdom to accelerate the Brexit - the exit from the EU if London is going to have time to complete the main part of this process this autumn.
"I think the concept of a shared customs space is something that we would like to see some new thinking on from the British side", he said before holding Brexit talks with other European Union ministers in Brussels. "The clock is ticking", German EU Minister Michael Roth told his EU peers meeting in Brussels.
The EU is pressing for "substantive progress" from Britain on the future of the border in Ireland in time for a crunch European Council summit just six weeks away.
The EU says Britain must agree to a workable solution to the question of how to avoid a hard border between EU member Ireland and the British province of Northern Ireland by the June 28-29 summit.
May's spokesman, however, said the "focus is on getting this right" rather than meeting a deadline. "I haven't put a timeframe on the completion of that work", the spokesman told reporters.
Diplomats and officials in Brussels note little progress in Brexit negotiations since the European Union leaders last met, raising doubt about whether the bloc and London would be able to mark another milestone at the next top-level summit on June 28-29.
Ms May's chief of staff Gavin Barwell gave Tory MPs what one called "a technical briefing" on the advantages and flaws of the two customs options being considered by ministers and which have split the cabinet. It would see Britain collect tariffs on behalf of Brussels on goods from non-EU countries set to be re-exported to the continent. Under a second idea, for a streamlined customs arrangement, traders on an approved list would be able to cross borders freely with the aid of automated technology. "I very much hope we will agree but there are no guarantees, unfortunately".