“This is a tinderbox.”

Ham & High: The much-maligned honesty box Hampstead Heath swimming ticket machines. Picture: Joshua ThurstonThe much-maligned honesty box Hampstead Heath swimming ticket machines. Picture: Joshua Thurston (Image: © Joshua Thurston - All Rights Reserved)

Swimming groups urged Hampstead Heath bosses to avoid inflaming tensions and "destroying goodwill" as City of London Corporation (CoLC) officials confirmed compulsory charging to use the bathing ponds would be recommended in March.

At a meeting of the Heath Swimmers' Forum on Tuesday, officials confirmed plans to ditch the "honesty box" system of charging that has operated since 2005 in favour of compulsory charges.

Explaining the CoLC's position, Heath supertintendent Bob Warnock - the officer in charge of Hampstead Heath - was met with cries of "shame" from swimmers.

He said: "Our position is that, as we have set out. Going forward we need the income from the ponds to support the costs of the ponds. We recognise it will still be a subsidised service but we will submit to move to a system where there is an applied set of swimming charges."

Ham & High: The Hampstead Heath Mixed Pond. Picture: Joshua ThurstonThe Hampstead Heath Mixed Pond. Picture: Joshua Thurston (Image: Submitted)

Swimmers' reps had set out a joint position before the meeting - urging the CoLC to improve the rate of voluntary contributions instead.

As the meeting closed, Nicky Mayhew, co-chair of the Kenwood Ladies' Pond Association, called the situation a "tinderbox", saying: "I would ask you not to spend a great deal of money changing what makes these ponds unique."

Margaret Dickinson, from the Mixed Pond Association, added: "It would be a very unfortunate move to try and decide that you are going to make drastic changes in a rush now."

Chairing the meeting, the CoLC's Karina Dostalova said: "Given the HSE report, we now have a responsibility to know just how many people are in the water at any one time and we need to know how many are in the facility.

"I will commit to feeding back your messages as we have heard them."

The CoLC began a review of swimming arrangements after receiving Heatlh and Safety Executive advice that it needed to increase lifeguard numbers.

At the meeting, officials were also told the move could jeopardise relations between the CoLC and pond-users, and that the CoLC was "unnecessarily" conflating safety issues and introducing charges.

Ms Dostalova confirmed it was likely there would be a "phased approach" to introducing the changes.

The decision is to be finalised at March 11's meeting of the CoLC's management committee.