London Marathon runners could be in for a gloomy morning on Sunday with forecasters predicting rain will “never be too far away”.

The Met Office said the capital will not see “desperately unpleasant conditions” but warned of cloud and rain potentially coming from the south-west.

The 26.2-mile race will start at Greenwich Park with runners heading to the finish line on the Mall near Buckingham Palace.

A Met Office spokesperson said: “The current thinking is that through the morning there’ll be rain encroaching from the south-west, over to the London area. It will be cloudy, with rain never too far away.”

Weather experts also said temperatures at the start line will be around 12C to 13C, and peak later in the day at around 16C or 17C.

The spokesperson added: “The weather will be highly dependent on how much cloud breaks in the afternoon. If it breaks, we may see temperatures scrape 18C or 19C.”

They added that “spectators may need to bring an umbrella, as weather may not be the best when standing around”.

Three of England’s Lionesses will be setting off the starting klaxons, with Leah Williamson sounding the first buzzer at around 8.50am when the wheelchair races begin.

Ellen White will start the women’s elite race at 9am, while Jill Scott gets the elite men and the mass race of close to 40,000 starters under way by 10am.

The Met Office said the rest of the country will see “outbreaks of rain moving eastwards across the south, perhaps heavy in places” on Sunday.