Sussex's main rail operator wants safety rules to be overturned because they are "not economically viable".

South Central has calculated spending £7.5 million altering ageing slam-door carriages would save one life a year.

The company, with South West Trains and Connex South Eastern, has asked the Health and Safety Executive for a relaxation on implementing the regulations.

But commuters have accused the company, which runs the Brighton to London route, of putting money before lives.

Father-of-two Richard Lovelock, 38, from Pound Hill, Crawley, said: "It's disgusting.

"As a family man I don't think you can put a price on human life. Trains should be as safe as possible and I don't think South Central's are.

"If the infrastructure is falling apart, then trains should be doubly safe."

South Central has been ordered to alter its 600 slam-door carriages to prevent them mounting each other and crushing passengers in a collision.

It has until the end of the year to fit the "cup and cone system" or decommission carriages.

At least 40 people have been killed in two major rail crashes, at Cowden, Kent, and Clapham, London, because 40-year-old carriages were weaker than modern rolling stock.

A spokesman said slam-door carriages were to be replaced anyway by the end of next year, when new trains came into service.

He said: "It wouldn't seem economically viable to have the cup and cone system in place for just one year."

Shelley Atlas, of Brighton Line Commuters Association, said: "They get enough money from passengers. We should all expect 100 per cent safety."