The firm chosen to take over most Sussex trains could move in early if current operator Connex runs down its services, a Government minister has warned.

Govia, which runs the Thameslink Brighton-Bedford service, is due to take over the South Central franchise in May 2003.

MPs including Mayor of London Ken Livingstone fear that could mean Connex running down its operation before the contract runs out.

Discussions are currently taking place between Govia and Connex about the handover.

In the House of Commons, Liberal Democrat MP for Carshalton and Wallington Tom Brake called for Govia to be allowed to take over next year as the company wanted.

He said: "A protracted handover could lead to staff departures, which could cripple Govia's ability to run the service."

Transport minister Keith Hill told him that if Connex services deteriorated before the handover date there was a possibility Govia could take over early.

Mr Hill confirmed that infrastructure on the Arun Valley line, which runs through Horsham, Arundel, Littlehampton and Bognor, would be updated in 2004.

He said there would be major improvement to the Brighton line two years later, which could lead to a faster rail link to London.

Faster train services could be running between Hastings, Eastbourne and Portsmouth on the Coastway route by 2004 after track improvements.

Slam-door rolling stock will be phased out by the end of 2001. Almost 400 new carriages will be delivered by the end of 2002 and a further 334 by 2004.

Govia will name its new operation the New Southern Railway to rekindle memories of the heyday of the Brighton Line.

In the Thirties the Southern Railway's fast, bright green electric trains, running on newly electrified third-rail tracks, were among the most advanced in Britain.

Govia has promised to install passenger load monitoring equipment on all its trains to avoid overcrowding.

It says it will spend about £200 million on improving stations and 37 will be developed as community and retail centres.