From May 2, it will be compulsory to pay to use the Hampstead Heath bathing ponds, and the basic entry fee will double.

At a Wednesday meeting of the City of London's (CoLC) Hampstead Heath managememnt committee resolved to go against the advice from its own consultative committee and vote through officer recommendations.

Swimming groups and that committee had both argued for a measured approach which would see the CoLC improve efforts to make voluntary payment easier, but members of Wednesday's committee were not comfortable 'indulging' the swimmers.

Afterwards, one regular at the Ladies' Pond, Barbara Massey, said: 'It just feels like somebody has besmirched our pond. They have not understood.'

Another ladies' pond swimmer, Mary Powell, told this newspaper: 'I felt like I wasn't represented at all at that meeting. They didn't talk about how the City makes it very difficult to pay currently.

'I really feel for the frontline Heath staff who will have to implenent this. Who has thought throught the risks to the lifeguards?'

David Gilbert, a men's pond swimmer, added: 'What they haven't understood is how this will affect the ponds. They haven't worked it out.'

At the meeting, the Heath and Hampstead Society's John Beyer was one of few to speak in favour of retaining a voluntary system, at least for 2020.

He said the society thought 'that is a better option because it is moving forward towards a better charging system'. He added: 'We believe everyone should pay, The difference is how you get there - whether by persuasion or by compulsion.'

But others, including CoLC Alderman Gregory Jones disagreed. Alderman Jones said: 'The starting point is the health and safety advice, we can just wait in case there's another accident.'

He continued: 'I just don't think more money from the City should be spent on comms. If they [swimmers] don't understand self-policing, I don't think we should paying public money to convert people who are not regular swimmers.

'I also fear I do not respond well to underlying threats.'

In a statement afterwards, committee chair Karina Dostalova said: 'These changes will ensure our swimming facilities remain safe and stay inclusive as part of a sustainable mode of management so they can be enjoyed for years to come.

'We recognise the Heath's ponds bring many benefits to those who visit and take time out from their busy lives.'

The CoLC said the new charges, £2.40 for concessions, £4 for adults, and a package of freezes to season tickets and free swims for the over 60s and under 16s early in the mornings would keep the ponds accessible, while making sure there management is sustainable.