A Norfolk bus operator has pledged to not 'walk away' from a threatened coastal service that has boosted tourism and access in one of the country's most beautiful areas.

Funding cuts and a drop in government fuel tax subsidies have forced Norfolk Green to impose big fare hikes and cut some journeys on its Coasthopper service - which operates during the tourist season on the coast road between King's Lynn and Cromer.

And, while promising to fight on, managing director Ben Colson said Norfolk Green could not afford to 'suffer a financial loss simply for the wider social benefit'.

The service has seen a surge in users, from 240,000 in 2007 to 585,000 in 2011, with more and more people taking advantage of the chance to hop on and off the bus at beauty spots in north and west Norfolk.

But, in a letter to all of the parish councils that are on the Coasthopper route, Mr Colson said financial pressures were mounting for the service.

He said the summer timetable, which begins on April 6, would see fares rise by 'about four times the rate of inflation', while some journeys would be cut and more users would have to change from one bus to another en route.

Advertising of the route would cease 'outside the immediate area', while Norfolk Green would be 'cutting back significantly' the 350,000 print run on timetables.

He said: 'Norfolk County Council has decided to change its policy in respect of bus service funding, and this means that from April 2011 the amount of funding received for this route has been declining.

'We faced a cut last April and are facing a cut doubly as severe this year. All their funding may cease altogether in April 2013 when the current operating contract come to an end.'

Additionally, until this year, the government reimbursed 80pc of fuel duty paid by the Coasthopper service. This year, it has dropped to 64pc.

Mr Colson said the rebate was paid according to the amount of miles on a route and 'high mileage routes, such as Coasthopper' were hit 'disproportionately severely'.

He said ongoing negotiations with the county council had secured an outcome which 'whilst it means the standard of service will be less than in previous years, does enable the route to continue to a large extent without major timetable cuts'.

Mr Colson added: 'If central government and the county council decide that they are unwilling to do their bit for the local community in the area, then we cannot suffer a financial loss simply for the wider social benefit, because that means higher fares or service losses for our customers elsewhere, and that is not fair on them.

'You may be assured, however, that, having built the route - with the county council's active assistance - from 1996, to the nationally renowned bus route that it is today, we do not intend to simply walk away from it when the going gets tough.'

Tony Faulkner, chairman of Blakeney Parish Council, said the service was 'tremendously well used'.

He said: 'It's enormously important because it enables people to not have to use their cars. It's so attractive to go along the coast a little way, stop at a village, walk to the next one and catch the Coasthopper back.

'It encourages visits to the area of outstanding natural beauty, and when people are here they spend money.'

Tracy Jessop, assistant director of travel and transport services at the county council said: 'We recognise the importance of the Coasthopper, which is why we invest some 15pc of our support subsidies in this single service.

'We will continue to work with operators and stakeholders to try to ensure the service remains sustainable and deliverable in the future.'