A decision on a public inquiry into the Potters Bar rail crash will not come before next spring, according to Transport Secretary Alistair Darling.

The response came after North West Norfolk Tory MP Henry Bellingham on Tuesday demanded a public inquiry into the crash.

Mr Darling said: "It is necessary for a large amount of information to be gathered and processed before the prosecuting authorities can make their decision".

He said he would decide whether a public inquiry was appropriate after receiving the third interim safety report from the Health and Safety Executive (HSE).

Legal action

"I share your frustration at the length of time it is taking to bring to a conclusion not just the Potters Bar investigation but also the Hatfield and Paddington inquiries", Mr Darling said.

Seven people were killed and more than 70 injured when the rear coach of a West Anglia Great Northern train heading for King's Lynn in Norfolk became derailed 150 yards south of Potters Bar station in Hertfordshire on 10 May.

Victims said they would take legal action themselves if no-one admitted responsibility for the crash.

An HSE report in May found that faulty points caused the train to derail, but no party has been found responsible for the disaster.