OFFICIALS last night defended a £500,000 airport shuttle bus service after it emerged an average of only 28 people a day were using it.

The free half-hourly Sky Express service, paid for by grants from development agency One NorthEast and the Tees Valley and County Durham Economic Partnerships, links Durham Tees Valley Airport with the centre of Darlington.

It started last month amid a fanfare of publicity, but many of its journeys since have struggled to attract more than a handful of passengers, while it has been empty several times.

According to Durham Tees Valley Airport, about 1,000 people used the service in its first five weeks -an average of 28 a day.

Last night, airport and One NorthEast bosses stressed it was still a new service, with numbers in line with those expected, and that the people using it should rise.

Hugh Lang, managing director of Durham-Tees Valley Airport, said: "It should be pointed out that this is a long-term project which forms part of our overall plans for improving transport links to the airport.

"What we are looking for is a steady pattern of increasing numbers of people deciding to use the opportunity of travelling from home by rail and then being taken direct to the terminal on Sky Express."

He added: "That is what is happening and the numbers so far are very much in line with what we expected at this stage.

"All the evidence at this early stage shows that, as awareness of Sky Express increases, so do the passenger numbers, and we are working closely with airlines, tour operators and travel agents to promote the service."

John Holmes, the director of regeneration and tourism at One NorthEast, said: "The service is being monitored in conjunction with the Tees Valley and County Durham Economic Partnerships and Durham Tees Valley Airport and while it is still in the early days, the number of passengers using the service has increased steadily, and we expect numbers to continue growing."

The service, which uses two 24-seat buses supplied by Arriva, picks up from Darlington train station and the Dolphin Centre, in the town, and is part of multi-million pound expansion plans for the airport.