Tories vow to create northern powerhouse ahead of polls

London

THEY were among Britain's most durable stereotypes and, for some, they still are: the flat-vowelled northerner in an equally flat cloth cap, denizen of dark and distant mill towns; and the silver-tongued southerner, the city gent with bowler hat and furled umbrella, emblem of the capital's bright lights and prosperity, the magnet of the nation.

In recent days, the urge to close that unbridgeable gap has seemed to underlie the government's promise to turn a string of cities athwart the Pennine Hill…