A Greater London Assembly (GLA) debate on the way forward for the Royal Parks heard chief executive Mark Camley pledge that the organisation would continue to focus on "making better use of our assets".
The GLA environmental committee met to discuss the formation of a new board for the parks and how to deal with a 25 per cent cut in cash support from the coalition.
Deputy mayor for planning Sir Richard Lister insisted: "The mayor's priority is to preserve the parks as they are because Londoners want green oases without too much commercialisation.
"He is not looking for great changes. Yes, they have to find more efficient ways of doing things, but he will work closely with the board. We have already done this successfully with the Olympics.
"We are under pressure from the GLA to take out back office costs. But the Royal Parks have to get their head around how they will make up the substantial shortfall - more sponsorship and events or going to other people to raise money."
But assembly member Tony Arbour said the mayor's "overriding principle of ensuring no change in the parks does not appear compatible" with a need to generate income. Introducing car parking charges, for example, would make them "very different from what they are now", he pointed out.
Camley, who was called to the meeting, said there were no plans to charge for parking and grants had been cut every year for the past six years.
"What we do is look at what is core to the parks. We have looked at different ways of handling arts and education and making better use of our assets."
As an example, he said the Magazine Building, which used to store flagpoles for the Mall, was turned into a gallery to raise rental income. This had no impact on park users but raised cash. Income generated from better use of buildings raised around £1m a year.
Meanwhile, philanthropic sources, such as the US Tiffany & Co Foundation had raised $1.25m for fountains, said Camley said.
Arbour countered that the Diana memorial fountain was a "millstone", but Camley said it cost less to maintain than the nearby Albert and Queen Victoria memorials.
"While this isn't a wholesale transfer of the parks we have had clear assurance from ministers that this is a strong devolution package. The new board is the most cost-effective way to give Londoners a say in how the parks will be run. A full transfer model is on the table for the devolution."
Jeff Jacobs, head of paid service and executive director, Greater London Assembly