Simon Montague: "Serious risk of derailment from broken rails alleged"

The rail regulator has demanded an urgent report from Railtrack over the poor condition of the tunnel, which links England and south Wales.

The Health and Safety Executive (HSE) reduced the limit in the tunnel from 70mph to 20mph on Thursday following four incidents of broken rails in the tunnel over the last seven months.

'Utterly unacceptable'

The situation has sparked severe criticism from senior government ministers.

The Transport Minister, Dr John Reid, said passengers deserved a decent train service.

Drivers will have to go slow in the tunnel

"I find it utterly unacceptable that passengers should have to pay the price for Railtrack's failure to maintain track in the Severn tunnel," he said.

"Of course, safety is paramount and the speed restriction is necessary to reduce the risk of derailment or injury should a derailment occur. I am looking for a speedy resolution of this problem so that passengers can once again get the service they pay for."

The Deputy Prime Minister, John Prescott, has also written to Railtrack demanding an explanation.

The speed restriction is affecting trains between South Wales, London and Bristol.

Services between London Paddington, Bristol Temple Meads, Cardiff Central and Weston-super-Mare are experiencing cancellations or delays.

Huge fine

Inspectors have warned Railtrack that if it refuses to comply, the company could face a fine of up to £20,000, and individual directors could be prosecuted.

Chris Bolt, the rail regulator, has demanded an urgent explanation from Railtrack on the failure of its maintenance procedures.

Railtrack said it was disappointed by the decision to reduce the speed limit for trains using the tunnel.

A spokesman said the decision by the HSE had nothing to do with the current maintenance programme.

The tunnel had been closed for four weekends, with another two scheduled as part of a repair programme costing between £4m and £5m, he said.