BRITAIN'S top counter-terrorism officer has resigned this morning after his blunder threatened a major anti-terror swoop.

BRITAIN'S top counter-terrorism officer has resigned this morning after his blunder threatened a major anti-terror swoop.

Assistant Commissioner Bob Quick's downfall came after he was pictured outside Downing Street yesterday clutching sensitive documents prior to a meeting with Prime Minister Gordon Brown and Home Secretary Jacqui Smith.

The documents showed top secret details of a major anti-terror operation in north-west England, and forced the operation to be brought forward.

London Mayor Boris Johnson said he had accepted Mr Quick's resignation with “great reluctance and sadness”.