Britain's new Prime Minister Boris Johnson has begun his term in characteristically dramatic fashion, stacking his Cabinet with pro-Brexit politicians and delivering a gung-ho speech in which he vowed to take Britain out of the European Union by Oct 31, come what may, even without an agreement. The promise of delivering Brexit at any cost was what elevated Mr Johnson to the premiership with the backing of the Brexiters within the ruling Conservative Party. This vision collides, however, with some grim realities, which Mr Johnson will now have to face.

One is parliamentary arithmetic. The Conservative Party, together with its coalition ally, the Democratic Unionist Party of Northern Ireland, has a wafer-thin working majority in the 650-seat House of Commons. Moreover, a significant number of Conservative MPs are non-Brexiters. Mr Johnson is thus leading a deeply divided party.