With Brexit mandate in hand, U.K.’s own union faces new strains

Last week’s decisive victory for Prime Minister Boris Johnson has snapped years of debilitating uncertainty over the United Kingdom’s wayward path out of the European Union. The constitutional setup within the U.K., however, may be on a rockier road after an election that deepened its post-Brexit fissures.

In England, Mr. Johnson’s pro-Brexit Conservative Party swept the board, winning a clear parliamentary mandate for the U.K. to leave the EU on Jan. 31. The Conservatives also made gains in Labour-dominated Wales. A majority in both nations voted to leave the EU in the 2016 referendum. 

Scotland and Northern Ireland, in contrast, voted to remain. And nationalists in both places see Brexit as a made-in-England rupture with Europe that has shaken loose the already strained bonds of the U.K.’s multinational construct. Further constitutional challenges to London’s writ are inevitable, raising the possibility that Brexit – a nationalist

A Scottish mandate?A symbolic advanceBrexit lessons cut both waysThe next flashpoint