Thousands of runners are gearing up to take part in today’s annual London Marathon – with temperatures expected to soar to 20C.

Participants will make their way through the historic course from Greenwich to the Mall on what is expected to be a bright and sunny day, with the occasional rainy spell.

The 46th edition of the event is set to feature Sir Mo Farah and rugby World Cup-winning captain Ellie Kildunne as the official starters for all three races.

The current course record set by Kenyan runner Sebastian Sawe is also thought to be under threat – after he won last year’s edition in two hours, two minutes and 27 seconds.

His main rival is Ugandan Jacob Kiplimo, the Chicago Marathon winner and last year’s London runner-up.