Councillors decided – by a single vote – against accepting a £60,000 grant from the Government for its Free Swimming Programme at an extraordinary meeting on Monday.

They turned down £24,380 for each of the next two financial years, together with a one-off grant of £12,047, which might have been used to make improvements to Derwent Pool.

A similar Government programme to offer free swimming to the over-60s was backed by the council last month.

"My main reason for wanting to accept this offer from the Government is the health and fitness of our young people and this business of getting a lifelong pattern of improvements in health and fitness," said Cllr Jane Wilford.

But in a report to councillors, corporate director Paul Cresswell said the authority would need to find £35,000 from its budget to cover the cost of running junior swims if, as estimated, there was a 70 per cent increase in demand to use the facilities.

And, with the council in a "difficult financial position" during the current economic climate, he added members would face even tougher decisions when they came to make £500,000 of savings to balance next year's books.

Cllr Linda Cowling said there had not been enough thought about the "impact on our budget", and added the council already subsidised swimming by its support of Community Leisure Ltd, which manages the district's swimming pools.

Describing the offer as a "poisoned chalice", Cllr John Raper, chairman of the council, feared the increased demand could lead to "angry people" unable to use the facilities.

He added: "Common sense is telling me that it would be remiss of me to accept this as it an ill-thought out from the Government's point of view. I would rather have the money and try and make our facilities work through Community Leisure than have a free for all."

Speaking after the meeting, Cllr Howard Keal said there was not a "shred of evidence" to suggest council tax would go up as a result of the programme.

"It was based on unlikely assumptions on a massive increase in the level of uptake for free swimming which took no account of the limits on access to sessions," he said.

"Even if the worst predictions had been realised, the council as the funder for Community Leisure, could have adjusted future grant to avoid any increase in overall costs."

Cllr Keal added: "As I said on Monday night, this wasn't just looking a gift horse in the mouth, it's socking it in the jaw. A desperately poor decision."

Eleven councillors voted against accepting the grant, with 10 in favour and one councillor abstaining.