“Get Brexit Done.” That was the slogan repeated on every billboard, pamphlet and doorstep during the Conservative Party’s campaign for the U.K. election, held on Thursday.

And when the results came through overnight, it was clear those three words had helped win Boris Johnson’s party an overwhelming majority, with at least 364 seats in parliament up from 318 two years ago, the party's biggest victory since the 1980s under Margaret Thatcher.