One in five Sussex trains fails to arrive on time, according to figures released today.

Records also show that on longer journeys to and from the county, one service in three was late.

The figures have been revealed in a report by the Strategic Rail Authority, which found that while overall punctuality on the rail network had improved, passenger complaints were up.

The report examined train times from April to July this year.

Thameslink, which runs services across London between Bedford and Brighton, is the worst offender when it comes to running late.

Only 76.5 per cent of its rush-hour trains and 79.2 per cent of its daytime services arrived within five minutes of the scheduled arrival time.

Sussex's main train operator South Central, which operates services from Brighton to London and along the Sussex coast, fared better.

A total of 84.5 per cent of its daytime services and 84.7 per cent of rush-hour services were within five minutes of schedule.

The Strategic Rail Authority, which now has overall control of operational rail policy, said overall performance had been steady and passenger journeys were up but so were complaints.

The quarterly performance figures show 84.2 per cent of all trains in Britain ran on time between April to June 2003, up from 83 per cent during the same period last year.

The train operators which run into Sussex and showed an improvement included South Central and Gatwick Express, which has almost a 90 per cent record of getting its trains to arrive on time on the short journey between the airport and London Victoria.

Virgin Cross Country, which runs trains into Brighton from North-West England and Scotland, also showed a slight improvement.

But the Virgin Cross Country services only managed to get 70.2 per cent of its services in on time, an improvement on the 68.5 per cent of the same period last year.

Connex South Eastern, running through Kent to Hastings, was one of the train companies to show a deterioration in timekeeping, with 84.1 per cent of its daytime and 80.9 per cent of its rush-hour services arriving within five minutes.

South West trains and Wessex trains, which run services into Brighton, both showed a two per cent improvement in punctuality, with 77.9 and 85.1 per cent arriving on time.

A spokeswoman for the Strategic Rail Authority said: "There has been an upward trend but there is room for improvement.

"We remain concerned about the timekeeping of the long distance services. Some of the timetable changes should see an improvement."