Plans to extend a steam railway are under threat after it emerged that land it is due to be built on could be turned into a superstore car park.

Land earmarked for the extension of the Bluebell Railway to East Grinstead may be sold for extra parking at Sainsbury's.

The railway preserves a five-mile stretch of the former Lewes-East Grinstead line between Sheffield Park and Horsted Keynes.

It is hoped the proposed extension would bring tourism into the town and boost trade.

But Sainsbury's has been in talks with Railtrack and the Bluebell about the possibility of buying the land for a car park, although the supermarket giant said nothing had been decided.

Spokeswoman Emma Garner said: "We have spoken to both Railtrack and the chairman of the railway but it's very early days and there is nothing in the pipeline.

"These are very tentative discussions at this stage to see if there is anything worth pursuing and if anything does happen it will be in the interests of all three parties."

But the news has sparked an outcry from community leaders, who fear that losing the Bluebell extension would be a big blow to the town's economy.

Simon Kerr, tourist information officer, said it would be "a disgrace of national proportions" if the land were sold.

A spokeswoman for Mid Sussex District Council said: "We are very keen that the last stage of the railway is completed.

"We want it to go ahead and we hope Sainsbury's and Railtrack would help to see the last part of it completed. We would be very much against anything that stopped that happening."

Although there is no imminent deal, the Rail Regulator, which can approve or turn down the sale, has given consultees until November 5 to make their comments.