The Metropolitan police is preparing for what it described as potentially “one of the busiest days for policing in recent years” as tens of thousands of people are expected to descend on central London for two major demonstrations.

Armoured vehicles, horses, dogs, drones and helicopters will be deployed along with 4,000 officers to police the far-right Unite the Kingdom (UTK) rally organised by Stephen Yaxley Lennon, otherwise known as Tommy Robinson.

The Guardian understands officers will be granted extra powers to carry out a stop and search without requiring suspicion of an offence, which will also apply to the pro-Palestine Nakba Day rally taking place in a separate location to the UTK march.

At the same time, tens of thousands of football fans are expected at Wembley stadium for the FA Cup final.

For the first time at a demonstration, police will use live recognition cameras and organisers will be held personally responsible for the behaviour of the speakers they invite.

Deputy assistant commissioner James Harman said the “unprecedented” operation could cost the force £4.5m, adding that today “has the potential to be one of the busiest days for policing in London in recent years”.

Police estimate that about 50,000 people will attend the UTK rally, while the pro-Palestine march is expected to draw between 15,000 and 40,000 peope. The UTK rally last September overwhelmed expectations after more than 150,000 people flooded Parliament Square in Westminster.

Prime minister Keir Starmer said the rise of the far right represents “a fight for the soul of this country”, adding: “The Unite the Kingdom march this weekend is a stark reminder of exactly what we are up against. Its organisers are peddling hatred and division, plain and simple.”

The Guardian’s police and crime correspondent, Vikram Dodd, has the full report here: