London Marathon runners could face heavy rain for much of the race

Tens of thousands of people running this year’s London Marathon could be drenched in heavy rain for much of the race, forecasters have warned.

The Met Office has predicted a “very wet” Sunday in the capital with a higher than 50% chance of downpours persisting through a nine-hour window from 7am until 4pm.

Jonathan Vautrey, a spokesman for the forecaster, said runners will experience temperatures of around 10C.

He said: “More persistent rain is pushing across south-eastern England throughout the day – that could provide for a relatively wet and damp London Marathon.

“You will see temperatures across the south climbing no higher than 9 or 10C.”

Sunday’s race is set to be the largest ever London Marathon, with at least 45,000 people due to take part in the mass participation event, up from 40,643 in 2022.

This includes runners classed as non-binary for the first time, with 118 people who identified as gender-neutral on their entry forms taking on the challenge.

Organisers have said this is part of an effort to make the race “the most diverse, equitable and inclusive marathon in the world”.

They added that an LGTBQ-friendly “carnival energy” will be channelled on a 250-metre leg just past the 21-mile mark on Butcher Row, renamed Rainbow Row for the event.

This stretch was introduced in 2022, and directors have said it will be “bigger and better this year”.

Women will also be able to access free sanitary products throughout the race for the first time and use ‘Peequals’ – female urinals which have been tested at music festivals including Glastonbury.

Famous faces taking part include The Crown star Josh O’Connor, and Mumford & Sons frontman Marcus Mumford, who is raising money for the Grenfell Foundation.

EastEnders actors past and present will also take on the challenge in memory of Dame Barbara Windsor, raising money and awareness for Alzheimer’s Research UK.

A total of £60 million is expected to be raised for charity.

Great Ormond Street Hospital (GOSH) Children’s Charity is the official charity of the year, and it will be using the partnership to launch its fundraising appeal for a new children’s cancer centre.

Sir Mo Farah, 40, who has a personal best time of 2:05:11, will be among the elite marathon runners for the final time, and he admitted there could be tears after the race.

The world’s fastest marathon runner, Eliud Kipchoge, 38, from Kenya – whose record stands at 2:01:09 – will not be competing this year but is the official starter for the elite men’s race and the mass participation event at 10am.

Marathon record holder Brigid Kosgei, 10km record holder Yalemzerf Yehualaw, and Olympic champion Peres Jepchirchir will be among those competing in the women’s race.

Kenya’s Kosgei holds the women’s record of 2:14:04.

Runners will begin the 26.2-mile route from Greenwich Park, looping past London landmarks including Tower Bridge and Trafalgar Square before crossing the finish line near Buckingham Palace.

The event also coincides with a nationwide test of the Government’s new public alert system, which will send a loud alarm to millions of mobile phones across the UK at 3pm.

Meanwhile, up to 50,000 Extinction Rebellion (XR) activists will be on the streets nearby, for the third day of a protest dubbed “The Big One”.

Members of the climate group have said they are coordinating with the race’s organisers and they do not plan to disrupt it, though spectators have been warned to avoid Parliament Square.

The elite races and mass participation event will be broadcast live on the BBC from 8.30am, as well as on the Red Button and iPlayer.