The 2022 London Marathon will take in place in October instead of April for the third successive year.
This year, up to 50,000 athletes will compete on the usual course on 3 October.
Another 50,000 people will complete the 26.2 miles at venues of their choice throughout the day, competing “virtually” via an app that enables runners to track and record their runs.
Organisers said the new 2022 date of 2 October would increase the likelihood of the race going ahead in its usual form.
“We are living in a hugely uncertain world – a world where different approaches to managing COVID-19 are being explored and executed,” event director Hugh Brasher said.
“We believe that by moving the 2022 event to October we give ourselves the best chances of welcoming the world to the streets of London, enabling tens of millions to be raised for good causes and giving people the certainty that their hard work and training will allow them to experience the amazing crowds cheering them every step of the way.”
The 2023 London Marathon has been confirmed in its traditional slot in the calendar and will be held on Sunday, 23 April.
This year’s race is set to be the biggest marathon ever staged anywhere in the world, according to organisers.
With 50,000 participants, the marathon will likely set a new record for the number of people to complete the traditional route in a given year. The previous finisher record was 43,000.
Last year’s marathon was awarded an official Guinness World Records title for the “most users to run a remote marathon in 24 hours” after 37,966 people competed virtually for the first time.
Although the events industry has benefited from the easing of coronavirus restrictions, ongoing travel restrictions are likely to have an impact on the number of spectators who attend the race this year.
The event typically draws tourists from around the world.
There have been growing concerns over the number of COVID-19 cases and deaths being recorded in the UK, and ministers have not ruled out reimposing restrictions in the future.
On Tuesday, new figures showed one in 20 deaths registered in the most recent week in England and Wales mentioned COVID on the death certificate – the highest proportion in more than four months.
A total of 10,187 deaths were registered in the week ending 6 August, of which 527 (5.2%) involved coronavirus.
This is the highest proportion of deaths involving the virus since March, according to data from the ONS.