London Marathon runners and spectators have been warned to expect travel disruption as train strikes are planned across the weekend of the race.
Services at key London rail companies Southern, Great Northern and Thameslink will start much later on Sunday 2 October, the day of the race, and will be "extremely busy", Govia Thameslink Railway said in a statement on Tuesday.
This follows a full day of planned strike action on the Saturday 1 October, with passengers warned that services will be crowded and to travel "only if absolutely necessary" because of Network Rail strikes.
Only those travelling a short distance on Sunday 2 October will reach the 9.30am start line on time, the railway franchise warned.
Trains will also finish earlier on the day tens of thousands of runners and spectators are set to pour onto the streets of the capital for the annual event.
Disruption will be more severe because of Aslef union train drivers striking at other train operators on Saturday 1 October.
There will be no service at all on many lines across London, south of London, or between Ely and King’s Lynn on Saturday 1 October and Saturday 8 October.
Govia chief Angie Doll said trains could finish as early as 4:30pm on Saturday 1 October.
"We’re particularly concerned for London Marathon runners, who will have been training for this special event for many months, hoping to raise millions of pounds for charity, and the spectators," she said.
"We urge the unions to work with the industry and come to a resolution," she added.
Addressing the issue, the RMT union pointed out the strikes happening ahead of the London Marathon and said its members are taking action to "maintain a safe, secure and accessible railway for all passengers".
The planned strikes come as Just Stop Oil protesters are preparing a mass demonstration to take place during the race at Euston, Paddington and Waterloo stations.
How planned train strikes are set to affect travel on the first two Saturdays in October:
Saturdays 1 and 8 October
There will be no service at all on many lines south of London, across the heart of London itself, or on the route between Ely and King’s Lynn
On Saturday 1 October, pre-planned engineering work will also stop trains running between Brighton and Three Bridges and between Balham and West Croydon via Crystal Palace
Only around 18% of trains across Great Northern, Southern and Thameslink will run with, crowding expected, particularly on first and last trains
Trains won’t start until 7.30am and will finish between 4.30pm and 6.30pm
Gatwick Express will not operate, although the airport will have a limited Southern and Thameslink service of eight trains an hour in each direction
Southeastern and Thameslink services will not run at all in the Greenwich area where the marathon is due to start the next day.
Sunday 2 October – the day of the London Marathon
Services will start later the morning after each strike, at around 7.30am
Morning trains are likely to be very busy
Many trains won’t arrive in central London much earlier than 9am. Only those travelling a short distance to the London Marathon will reach the 9.30am start line in time.Wednesday 5 October – services extremely busy
Strikes near or around the GTR network by Aslef train driver members at London Overground, LNER, Southeastern, East Midlands Railway and Greater Anglia
Gatwick Express, Great Northern, Southern and Thameslink services expected to be extremely busy
On the Tonbridge to Redhill route, where trains are normally operated by Southeastern drivers, a special timetable will run to support schools and is expected to be available in journey planners such as www.nationalrail.co.uk from 29 September.
Want a quick and expert briefing on the biggest news stories? Listen to our latest podcasts to find out What You Need To Know...