LONDON, Oct 31  — Delegates and journalists planning to travel by train from England to the UN climate summit in Scotland faced chaos today after a fallen tree closed the main line from London.

An overnight storm saw the tree knock out overhead power wires on the track between London and Glasgow, the only direct rail link between the two cities.

Some of those set to attend the opening day of the crucial climate conference in Glasgow were left stranded in the British capital and elsewhere along the west coast line after services were suspended.

"Due to the extent of the disruption for services heading north of London, we’re advising customers do not travel,” Avanti West Coast, which operates services on the line, said on Twitter.

The company added it would try to get passengers to their destination "via any reasonable route”.

Network Rail, which manages the UK’s railway tracks, said the tree fell on overhead electric cables in Northamptonshire, in central England.

"We’re working on a plan to remove the tree (and) then fully assess the damage so we can plan a repair,” it added.

Environmental journalist Cecilia Keating was among the COP26-bound passengers unable to reach Glasgow, tweeting photographs of an overcrowded concourse at London’s Euston station.

"Hundreds of delegates to a climate conference stuck in Euston because (the) UK’s infrastructure just isn’t resilient to climate change,” she said.

Another journalist, Pennie Taylor, reported being "turfed off a train at Euston that was packed to the gunnels with COP26 attendees”.

The travel chaos represents an inauspicious start to the 12-day gathering of world leaders and environmental delegates hailed as the "last, best hope” of limiting potentially catastrophic global warming.

Many climate activists had advocated travelling to COP26 by rail, with Swedish icon Greta Thunberg arriving by train from London yesterday.

Opponents of air travel argue that reaching Glasgow by train emits 14 per cent of the carbon emissions created by flying to the summit from London. — AFP