The London Marathon Could Become a Two-Day Race With 100,000 Runners

The Guardian broke the story on 25 March 2026. The London Marathon is in advanced talks to stage a two-day event in 2027, internally referred to as the "Double London Marathon." The proposal would split the race across Saturday 24 and Sunday 25 April, with 50,000 runners completing the course each day. Elite men's and women's races would run on separate days. The plan has not been formally approved, but reportedly has the backing of the Mayor of London's office.

Organiser London Marathon Events confirmed the direction of travel in a statement, saying they are "looking at the intention for the 2027 TCS London Marathon to take place across two days." This is the most significant structural change being considered in the race's 45-year history, and it comes directly from a demand problem that has become impossible to ignore.

Why This Is Happening Now

The numbers behind this decision are striking. Over 1.1 million people entered the ballot for the 2026 London Marathon. Three years ago that figure was 410,000. The race has not gotten significantly larger. The appetite for it has grown dramatically, and the odds of securing a ballot place have collapsed to around 1 in 55 as a result.

The 2025 race set a Guinness World Record for the largest number of finishers in a single marathon: 56,640 runners, raising £87.3 million for charity. That record will almost certainly be broken again in 2026. But with over a million people now applying each year and only around 15,000 to 20,000 ballot places available, the event has become a lottery in the most literal sense. The vast majority of people who want to run it will never get the chance.

What the Plan Actually Involves

The Guardian's reporting, based on what it described as advanced internal discussions, sets out the proposal in some detail. The 2027 event would be positioned as a one-off special edition, not a permanent change to the race format. The course would remain the same. The route from Greenwich and Blackheath through the City, across Tower Bridge, around Canary Wharf and finishing on The Mall would run on both days.

The decision to split the elite races is particularly significant. London's elite field is one of the deepest in marathon running: the 2025 women's race produced a world record from Tigst Assefa and the men's race featured Eliud Kipchoge, Olympic champion Tamirat Tola and eventual winner Sabastian Sawe. Staging those races on different days would give each field its own dedicated spotlight and potentially allow for larger crowds at the finish on The Mall.

What It Means for the Charity Numbers

The London Marathon is already the world's largest annual single-day charity fundraising event. The 2025 race raised £87.3 million. The proposal to expand to two days, effectively doubling the number of charity runners, comes with a target of raising over £130 million across the weekend. That would represent a roughly 50 percent increase on the current record and would have significant implications for the charities that rely on London Marathon entries as their primary annual fundraising vehicle.

What Would Actually Change on the Ground

Splitting 100,000 runners across two days rather than squeezing them all into one is not simply a matter of issuing more bibs. The logistics of a London Marathon day involve road closures across a significant portion of central and south-east London, volunteer coordination across hundreds of positions, medical coverage, transport disruptions, and spectator management at the finish. Doing this twice in a weekend is a substantially different operational challenge to doing it once.

The city would need to agree to two consecutive days of road closures across the same route. Transport for London, the Metropolitan Police, and London Boroughs along the course would all need to sign off. The Mayor of London's office backing is therefore a meaningful piece of this picture. Without City Hall onside, the operational approvals would be extremely difficult to obtain.

The Questions Still to Answer

The plan has significant appeal but also real complexity. A two-day event raises questions that do not have obvious answers yet.

There is also the question of what the precedent sets for the race going forward. Described as a one-off, the Double London Marathon would be framed as a special edition rather than a permanent format change. But if 100,000 runners complete the course in 2027 and the charity numbers break every record, there will be enormous pressure to repeat it. What begins as exceptional tends to become normal when the numbers work.

What This Means If You Run HYROX or Hybrid Events

The London Marathon and HYROX occupy adjacent territory in the British hybrid fitness scene. A large proportion of athletes who race HYROX also run road races, and London is on the list for most of them. The proposal to double the field means that the odds of getting a ballot place in 2027 would roughly double from the current 1 in 55, making it meaningfully more accessible for athletes who have been entering year after year without success.

For hybrid athletes specifically, the prospect of a Saturday elite race and a Sunday mass participation race also raises an interesting training scenario. If you are racing HYROX in the spring season and targeting London in the same year, two-day event or not, the challenge of balancing peak marathon fitness with HYROX station strength is the same. The difference is logistical, not physiological.

When Will We Know for Certain?

The Guardian's reporting describes the talks as advanced, with the Mayor's office backing already in place. London Marathon Events' official statement confirms the two-day 2027 intention is being actively explored. The most likely timeline for formal confirmation is the period around the 2026 race in late April, when organisers traditionally announce the following year's ballot. If the 2027 ballot opens in April or May 2026 with 100,000 places rather than the usual allocation, that will be the signal that the plan is proceeding.