A senior German lawmaker, an adviser to the French prime minister and a former deputy head of the Bank of England have proposed that a post-Brexit Britain form a new "continental partnership" with the EU.
In a paper published on Monday by the Brussels-based Bruegel think-tank, five experts argue that Britain be given a say in the affairs of a more closely integrated European Union in return for contributing to shared security and budgets as well as accepting a degree of easy immigration for European workers.
A key aim would be to avoid a rancorous split following the British vote to quit the Union on June 23, further diminishing the clout the continent will have in the world.
"Neither the UK nor the continuing members of the EU can escape their geographical interdependencies. Both have a stake in economic and political stability in Europe," they wrote.
"Today's volatile and dangerous world requires its nations to collaborate to confront new and multiple challenges. The longer-run prospect of a future world in which Europe is only one amongst many powerful regions demands the same."
The group comprises: Jean Pisani-Ferry, who runs policy planning for Socialist French Prime Minister Manuel Valls; Norbert Roettgen of German Chancellor Angela Merkel's Christian Democrats, who chairs the Bundestag foreign affairs committee; former Bank of England deputy governor Paul Tucker; Belgian economist Andre Sapir, a former adviser to the European Commission president; and Bruegel Director Guntram Wolff.
Some Brexit campaigners argue that geography matters less in the digital economy and that Britain should not barter sovereignty for access to the EU's markets.
Their advocacy of a deal, unlike that currently given to other non-EU states such as Norway or Switzerland, that would give Britain access to EU markets while accepting voters' rejection of full free movement for EU workers reflects types of Brexit compromise that officials are starting to think about.
British Prime Minister Theresa May has said she wants a new kind of relationship from those already set up by the Union.
The Bruegel authors suggest a Europe of two circles in which the EU core, bound more tightly than today around the euro - would consult with Britain and others like Norway, Switzerland and one day perhaps Turkey or Ukraine - giving outer members of such a Continental Partnership a voice but no veto on policy.