Rail travellers in Sussex suffered another day of misery today due to speed restrictions and safety checks.

Connex services were operating only an hourly service between Brighton and Victoria while Thameslink have cancelled several trains this afternoon and this evening.

The hourly 50 minutes past the hour fast Connex trains from Brighton to Victoria leave at 20 minutes past instead and are taking ten minutes longer.

Rail companies warned there will be further delays and cancellations on virtually all services throughout the country this weekend during track checks in the wake of the Hatfield rail crash.

Up to 300 sites on Britain's rail network face temporary speed restrictions.

Railtrack warned that delays could get worse before they get better as engineers identified 1,850 rails with hairline cracks in them - known as gauge corner cracking.

The problem was only identified within the past 12 months and is suspected of triggering the Hatfield crash, Railtrack said.

The discoveries have led to speed restrictions on tracks at 206 places in the country, but this is expected to rise as another 150 sites where cracks are "possible" are inspected.

This comes as Deputy Prime Minister John Prescott warned rail chiefs at a summit that passengers' patience was "being stretched."

But he admitted "inconvenience" would be inevitable to complete the major task of addressing safety issues on the network.

Thameslink has cancelled five services to and from Sussex this afternoon and tonight and warned traveller to expect overcrowding because some trains will have eight carriages instead of the usual 12.

The cancelled trains are the 15.35 Brighton to Bedford, the 16.05 Brighton to London Bridge, the 17.08 and 18.40 London Bridge to Brighton and the 17.27 Haywards Heath to London Bridge.

Thameslink services have been re-timed to run at eight minutes and 38 minutes past the hour and will take at least ten minutes longer due to speed restrictions on the line to and through London.