FILE PHOTO - Scotland's Brexit Minister Michael Russell arrives at the Scottish Parliament ahead of a referendum debate in Edinburgh Scotland, Britain March 21, 2017. REUTERS/Russell Cheyne

EDINBURGH (Reuters) - Britain should rule out the possibility of leaving the EU without establishing terms of its future relationship with the bloc, Scotland’s Brexit minister said on Monday, describing such an outcome as “unthinkable”.

Michael Russell was speaking before the visit of Britain’s Brexit minister David Davis to Brussels this week for a third round of negotiations with the European Union.

London last week published a series of position papers that broadly show it wants to keep close ties with the bloc without the costs the EU says that would involve.

Scotland, whose devolved nationalist government wants to keep EU single market membership, says the United Kingdom is engaged in “brinkmanship”.

“The (position) papers confirm the benefits of EU membership, yet bafflingly assume those benefits can be maintained while leaving the EU, Single Market and Customs Union – a position that has been met with derision,” said Russell, Minister for Negotiations on Scotland’s Place in Europe in the devolved government.

He said the British government’s Brexit position had failed to incorporate the opinions of devolved authorities in Scotland, Wales and Northern Ireland despite having committed to consulting them.

Prime Minister Theresa May has been under pressure to back away from her stance that “no (Brexit) deal is better than a bad deal” since losing her governing Conservative Party’s parliamentary majority in an ill-judged election gamble in June.

“The UK Government must make clear – without delay – that no deal is not only a bad outcome, it is an unthinkable outcome. More and more people across business and in our communities are expressing their concern at the damage being done to our economy and public services,” Russell said.

In last year’s Brexit vote, England and Wales voted to leave the EU while Scotland and Northern Ireland voted to keep membership.