The Metropolitan police have said organisers of this weekend’s Unite the Kingdom and March for Palestine demonstrations will be held responsible for any hate speech connected with the events, in what they expect to be “one of the busiest days for policing in London in recent years”. Tens of thousands of people are expected to march in the capital for the Unite the Kingdom event in central London and the Nakba: 78 March for Palestine from south Kensington to central London. Senior officers said protesters would face “the highest degree of control”. The FA Cup final is also due to be held at Wembley on Saturday. In a briefing, James Harman, a deputy assistant commissioner, said a “zero tolerance” operation of “unprecedented” scale would include 4,000 officers, at a cost of £4.5m, and “swift and decisive” action against disorder and hate speech. Live facial recognition will be used in an area of Camden where Unite the Kingdom attenders are expected to gather outside the event itself, “comparing the faces of those walking past, with the faces of those on a specific watchlist”, Harman added. It is not expected that facial recognition will be used on pro-Palestine marchers. Harman said: “For the first time, we’ve also imposed conditions relating to the speakers at these protests. “These conditions make the organisers responsible for ensuring that speakers they invite don’t break the law by using these events to platform from unlawful extremism to … hate speech. “Both the speakers and the organisers will face consequences if that happens.” He added: “If hate speech is used at the rally, we, the police will intervene, then and there with the speaker. Our condition places the responsibility on the organiser as well as the speaker to stay within the law.” Harman said armed police were “available