London Marathon bosses are in advanced discussions about staging a two-day race in April 2027, which could see a world-record 100,000 amateur runners pounding the capital's streets.
The proposal, dubbed the "Double London Marathon" internally, would split participants across Saturday 24 and Sunday 25 April next year, with roughly 50,000 taking on the course each day.
It's understood the elite men's and women's races would also be held on separate days, turning the weekend into a celebration of both professional and grassroots running.
While the mayor's office backs the idea, no formal approval has been granted yet.
The London Marathon looks set to go ahead over two days
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The demand for places has gone through the roof in recent years.
More than 1.1 million people threw their names into the ballot for the 2026 race – that's a massive jump from 840,318 applicants in 2025 and just 578,304 the year before.
But here's the tough reality: with 57,449 starters last year, only around 5% of hopefuls actually get to run.
The 2025 event saw a record-breaking 56,640 runners cross the finish line, cementing London's status as the world's most popular and oversubscribed marathon.
It's clear something needs to change to meet that incredible appetite.
Last year's London Marathon saw a record-breaking 56,640 runners cross the finish line
|GETTY
Sadiq Khan's office is firmly behind the plans, with a spokesperson saying: "London is the sporting capital of the world and the Mayor looks forward to working with London Marathon and partners to consider if it might be possible to host an event that will run across two days next year."
The charity angle is brilliant too.
Last year's race brought in a whopping £87.3 million for good causes, making it the world's largest annual one-day fundraising event.
Organisers reckon a two-day format could push that figure beyond £130 million – a massive boost for charities at a time when every penny counts.
A London Marathon Events spokesperson confirmed the organisation is actively looking at options, stating: "The TCS London Marathon is the world's most popular marathon, and we are continually exploring innovative ways to enable more people to take part, while delivering positive benefits for London."
They added: "Together with our partners and stakeholders, we are looking at the intention for the 2027 TCS London Marathon to take place across two days. No approval has been given at this stage."
For now, all eyes are on the 2026 race taking place on Sunday 26 April, with organisers focused on making sure every runner has an amazing experience.