Pupils stay at Hornsea Outdoor Residential Centre while visiting surrounding museums, shops and factories as part of the science, humanities and physical education curriculum.

But from September the cost to stay there will rise from £15.50 to £20 per night – in order to generate an extra £12,000 a year towards running it.

Schools in the Express area have hit back at the council’s decision saying it will put added pressure on poorer families.

Anne Jenkinson, headteacher of Burntwood J&I School, South Kirkby, said: “I am saddened by the recent increase in charges.

“I realise that a measure of the costs have to be passed on but if we go too far we will be making it inaccessible for poorer families. Children on free school meals get a good subsidy for visits to Hornsea but that leaves a lot of borderline families who find it very hard to find the full cost.

“In the past, even at the previous lower charge level, we have had to use school funds to subsidise many of our families. Sometimes it is not just one child going from a family, it may be two or even three.”

Mrs Jenkinson said that added costs of activities and educational visits also had to be considered on the trip.

Margaret Wildey, Moorthorpe Primary School headteacher, said: “Our pupils were only at Hornsea a week ago. The Hornsea Centre celebrated its 70th anniversary on Saturday but its future still remains uncertain.

“The centre has always given us good value for money but the price increase might now make it more difficult.”

In February council chiefs announced enough funding had been found for another year, but said sponsors were still being sought for future years.

Alison Delyth, Wakefield Council's service director for schools and lifelong learning, said: “The long-term future of the Hornsea Centre has not been decided. It is the case that its future would be more secure if it was self-financing and no longer needed to depend on a large financial subsidy from schools."