LONDON • Today was supposed to be Britain's first working day outside the European Union, the moment when, after a fierce political struggle fought over three long years, the United Kingdom of Great Britain and Northern Ireland finally threw away the shackles of European bureaucracy, shattered the chains of European servitude and strode proudly on to the global stage unbound and unfettered.

Ahead lay all the promises of abundant trade and prosperity. London, already Europe's financial capital, was bound to shine even brighter. And Britain was to become a "Singapore-on-Thames", a sparkling jewel on Europe's edge, a magnet for the world's business.