More than 2,000 officers will be on duty in London on Saturday to police the Champions League final, a protest organised by Tommy Robinson and a counter-demo.
Groups from across the UK linked to football disorder are expected to attend the event organised by Robinson, whose real name is Stephen Yaxley Lennon, the Metropolitan Police said.
London’s public transport network is also expected to be extremely busy, bosses have warned.
Borussia Dortmund will take on 14-time champions Real Madrid at Wembley Stadium on Saturday evening.
Robinson’s protest will set off from a meeting point in the Victoria area at about 13:00 BST and finish in Parliament Square, where speeches will take place and a film will be shown.
A static counter-protest, organised by Stand Up To Racism, will be in Whitehall from midday.
Conditions have been imposed on both protests to ensure they remain in specific areas and the Met said officers would be deployed “in significant numbers” to ensure those in Parliament Square and Whitehall do not come together.
Disruption is also expected on public transport due to the Champions League final.
While kick off is not until 20:00, Transport for London (TfL) said the Jubilee and Metropolitan lines were likely to be especially busy during the day with potential temporary station closures.
A four-day football family festival is also continuing in parts of the capital throughout the weekend.
Stations including Baker Street, Bond Street, Canary Wharf, Charing Cross, Embankment, Marble Arch, Waterloo, Westminster, Wembley Park and Wembley Central are expected to be particularly busy, according to TfL.
The transport body said short-term safety measures could come into force at some stations, such as queuing, temporary closures, trains non-stopping and changes to entry and exits.
People with tickets for the final have been advised to leave plenty of time to get to Wembley Stadium.
The football festival has been taking place at several sites in central London, including Trafalgar Square, Regent Street, Somerset House, the South Bank and Potters Field Park with road closures in place, as well as changes to some bus routes and Cycleways.
It is due to finish on Sunday evening.
Meanwhile, engineering work over the weekend means there are no direct train services between central London and Luton Airport, as well as no Elizabeth line services between Paddington and Abbey Wood.
Elizabeth line trains will also not run between Whitechapel and Stratford on Saturday.