Jonathan Edwards presents live coverage of the 33rd annual London Marathon, as world-class runners and 36,000 fundraisers compete in one of the world's most famous races.
The elite men's race has attracted all three marathon medallists from last summer's Olympics and six of the 10 fastest runners of all time. In addition, Britain's double Olympic champion Mo Farah will get his first taste of an elite marathon when he runs the first half of the course as a fact-finding mission ahead of his full marathon debut next year.
Farah will be up against the likes of marathon world record holder Patrick Makau, Olympic champion Stephen Kiprotich, world champion and Olympic silver medallist Abel Kirui, and reigning London champion Wilson Kipsang.
In the women's race, Ethiopia's Tiki Gelana defends the title she won last year but faces tough opposition from the likes of Kenyan world champion Edna Kiplagat and compatriot Priscah Jeptoo, who won silver at the London Olympics.
Great Britain's four-time London 2012 Paralympic gold medallist David Weir and compatriot Shelly Woods will defend their wheelchair titles.
The day for the majority of runners, though, will be about setting personal bests or simply completing the 26.2 mile course. We will hear from some of those who are running for the many charities who benefit from one of the great events in the British sporting calendar.
Colin Jackson, Denise Lewis, Phil Jones, Sonali Shah and Katherine Merry report from across the course, with race commentary by Steve Cram, Brendan Foster, Paul Dickenson, six-time London Marathon wheelchair race winner Baroness Tanni Grey Thompson and marathon world record holder Paula Radcliffe.