This year’s London Marathon will take place on a closed-loop circuit around St James’s Park on 4 October.
The event, moved from April because of the coronavirus pandemic, is restricted to elite athletes, who will be in a bio-secure bubble during race week.
The finish line will be in its traditional place on The Mall, with no spectator access to the course.
“We are confident we have created the safest environment for everyone,” said event director Hugh Brasher.
“Sports fans all over the world are eagerly anticipating these great races in this unique environment.”
The revised route will feature 19.6 laps, taking in The Mall, Horse Guards Parade, Birdcage Walk and the spur road running adjacent to the front of Buckingham Palace.
Kenya’s defending champion Eliud Kipchoge will take on Ethiopia’s Kenenisa Bekele, who went within two seconds of Kipchoge’s world record last year. (BBC)