Avanti’s west coast line was blocked because of a tree falling on power lines, the company said. It advised customers not to travel.
Passengers, potentially including hundreds of delegates and journalists heading to Cop26, were told their tickets for today could still be used tomorrow.
Network Rail said power lines near Long Buckby, about halfway between Northampton and Rugby, had been damaged.
“We’re working on a plan to remove the tree & then fully assess the damage so we can plan a repair,” the body tweeted.
Avanti has agreed with TransPennine Express that the latter will take some passengers on “reasonable routes”.
According to The Independent’s climate correspondent, Daisy Dunne, dozens of people are also stuck en route at Milton Keynes, attempting to find ways around the blockage.
She added: “It seems that all routes to Glasgow are currently suffering delays and official advice from the train companies is to go home and try again tomorrow, which is simply not possible for many.”
Simon Lewis said he had been stuck on a train for more than three hours. The 49-year-old climate scientist, from University College London, was on the 11am service from London to Edinburgh but has been stuck since 11.45am.
“We are moving a tiny bit every now and again, but have not made it to Peterborough yet, the first stop," he told PA Media.
“This is inconvenient and a reminder that climate change drives extreme weather events and every country needs to adapt.
“But a stopped train is nothing compared to the two million people displaced by flooding in Shanxi province in China, last month, and those facing famine today in Madagascar.”
Only yesterday, Avanti ran a dedicated “climate train” from London to the summit in Glasgow, providing the final link in a trans-European journey for some 300 activists.
The UK was lashed again by heavy rain and winds on Sunday, days after downpours blocked railway lines in northern England and Scotland. In some areas officials were forced to recommend people flee their homes due to rising river levels on Thursday.
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