In the 1949 Ealing comedy Passport to Pimlico, residents of the London district are declared foreign nationals and subjected to border controls. Now some senior City figures are dreaming of a sequel (maybe Visa for Victoria?) in which London declares independence from the rest of the UK, at least in terms of immigration.

The plot of the original film was gloriously silly, involving a 15th century property deal between Edward IV and the Duke of Burgundy. Some critics reckon the remake idea, designed to enable the City to retain access to skilled EU staff post-Brexit, is equally fanciful.