CORNWALL’S only mainline rail link to the rest of the country faces a fresh threat from crumbling cliffs and disappearing sand dunes, with a Cornish MP warning that a landslide could bring potentially catastrophic consequences.

Jayne Kirkham, Labour MP for Truro and Falmouth, told a Westminster debate there was a “very real risk” of a cliff collapsing onto a passing train along the vulnerable coastal railway between Dawlish and Teignmouth.

She warned that passengers and communities across Cornwall were being left exposed to the consequences of an increasingly fragile transport link.

“There is a very real risk that a cliff could fall on a train,” she told MPs, adding that people in the Westcountry were expected to put up with disruption that would not be tolerated elsewhere.

The railway is Cornwall's vital connection to the national rail network, with any serious damage potentially cutting off direct services into the county.

The consequences were seen in February 2014, when ferocious storms smashed through the sea wall at Dawlish, leaving sections of track suspended above the sea and severing the mainline.

Network Rail has since spent £165-million strengthening the route, including a new sea wall, a redesigned Dawlish station and measures to prevent sandstone cliffs collapsing onto the tracks.

However, the fifth and final phase of the resilience programme, covering the stretch between Parson's Tunnel and Teignmouth, has been put on hold indefinitely because of its cost.

Torbay Liberal Democrat MP Steve Darling said: “The cliffs are the enemy now, rather than the sea” – and warned disappearing dunes at Dawlish Warren could leave the railway at Powderham increasingly exposed as the Environment Agency pursues its managed retreat policy.

Richard Foord, the Liberal Democrat MP for Honiton and Sidmouth, added: “Passengers deserve railways that withstand the climate conditions that we are set to face. Too much of our infrastructure, particularly in the Westcountry, still relies on Victorian earthworks and drainage systems and assets that were not designed for today’s climate.”

Hotter summers and extreme weather were adding to the risks, with changing ground conditions potentially causing rails to buckle.

Department of Transport under-secretary Simon Lightwood, the Labour MP for Wakefield and Rothwell, said ‘all endeavours’ were being made and a great deal of funding had gone into making the track through Dawlish and Teignmouth as resilient as possible.

“I do not think that anybody wants to suspend services through that area,” he said. “But unfortunately, there will be instances where that may have to be done.

“The investment that has been put in has made it more resilient. We saw that during the latest storms, when the line was reopened the day after its closure.

“The new seawall performed as designed, helping to protect the infrastructure from major damage.”

He said investigative work was continuing on the unfinished final phase of the resilience project, including a drainage trial to remove water from the cliffs.