LONDON – London police braced themselves for their busiest day in years on May 16, when tens of thousands of protesters were expected to attend the latest rally staged by far-right activist Tommy Robinson.The British capital’s Metropolitan Police said it would deploy some 4,000 officers – alongside horses, dogs, drones and helicopters – to manage the march and a counter-demonstration merged with a pro-Palestinian protest, as well as the FA Cup final.The Met has imposed various conditions on the two rallies, over their routes and timings, in a bid to keep rival attendees apart.The force, which estimates the operation will...