AT LEAST 400 Al-Qaeda terrorist suspects — double the previous estimates — are at large in Britain, according to police and MI5. Dame Eliza Manningham-Buller, director-general of MI5, has said the figure could be as high as 600 if all those thought to have returned from combat training in camps in Pakistan, Afghanistan and elsewhere are included. The new assessment — effectively a “terror audit” of Britain — was confirmed this weekend by one of Britain’s most senior police officers, who warned that shortages of trained surveillance teams were undermining attempts to monitor all the suspects. “With about 400...