Implementing car parking charges in Richmond and Bushy parks will cost the Royal Parks Agency (RPA) nearly £3m – and will not make it a penny for more than six years, it has been claimed.

Following the revelation, opponents of the plans, including the majority of residents and politicians from across the political divide, organised a demonstration to be held later this month – and questioned the relevance of the RPA public consultation, which last year received 2,000 individual responses, 84 per cent of them against the proposals.

An RPA spokes- woman confirmed the plans required £2.9m set-up costs – £2.7m for improved new car parks in both parks and “ecological drainage” and £200,000 for a third part of the project traffic calming in Greenwich Park, south east London.

But, she added, the work “needed to be done” regardless of the charging plans.

But Putney MP Justine Greening said: “The charges are an integral part of their planned improvements. This is what [the RPA] described as coming directly from the introduction of the charges – it was in their impact assessment.

“There was no pressure on them to spend money to upgrade the car parks.”

The RPA expects Richmond Park drivers to generate £345,000 from parking revenue annually, with an additional £85,000 coming form Bushy Park users, meaning it will take more than six years to claw back costs.

The disclosure came after Culture Minister Margaret Hodge announced daily charges of £1 per hour, to a maximum of £3, in Richmond Park, last week.

Miss Greening branded the decision “a disgraceful waste” of taxpayers’ money and questioned the importance of the consultation.

“After the overwhelming opposition of local residents . . . the decision to press ahead with introducing car park charging is completely wrong,” she said.

“Ministers clearly have no idea how important our local environment is to us.”

Wandsworth Council leader Councillor Edward Lister added charges would make the park off-limits to those on low incomes, the elderly and families with children struggling with the financial effects of this recession.

He said: “What Mrs Hodge doesn’t want to acknowledge and what she doesn’t seem to recognise is visitors to the park have no choice about taking the car because the public transport options into the park are non-existent.”

Mrs Hodge said the fees were justified by research which showed 88 per cent of Richmond Park users were in the wealthiest ABCI socio economic group – a measure used to give an idea of households’ income.

In a letter, which also stated only 2 per cent came from the poorer, DE category, she said: “There is nothing to suggest that the imposition of charges, particularly at the levels proposed, cannot be afforded by those who use the parks.”

She added not proceeding with a six-hour maximum stay limit and increased cycling access would placate some residents’ concerns and, following a meeting with leaders from Wandsworth, Richmond and Kingston on Monday, agreed to look into the feasibility of expanding a bus services to the park.

Colin Buttery, deputy chief executive at the RPA, added the charges were “similar to the cost of a cup of coffee and compare favourably with car parks locally and at similar amenities”.

q A non-party political rally, on Saturday January 30, will begin at 10.30am in the car park at Pembroke Lodge.