English councils made a record surplus from parking charges of almost £700 million last year, according to a new study.
In 2014/15 local authorities generated £693 million from their parking operations after running costs were taken into account, motoring research charity the RAC Foundation found.
This is up from £667 million in the previous 12 months.
The Local Government Association (LGA) described the study as "misleading" and insisted surplus money is spent on transport projects.
But the RAC Foundation urged councils to reveal "exactly where this huge excess ends up".
%VIRTUAL-ArticleSidebar-council-stories%The organisation analysed parking data in financial reports from English councils.
The five authorities with the largest surpluses were all in London, led by Westminster (£46.4 million), Kensington and Chelsea (£33 million) and Camden (£24.5 million).
Brighton and Hove had the highest figure outside the capital at £18.6 million, with Nottingham City also in the top 10 at £13.3 million.
RAC Foundation director Steve Gooding said: "The financial sums involved in local authority parking are huge and the overall profits eye-watering. Once again the year-on-year direction of travel is upwards.
"It is unsurprising that London leads the way in making money. Its roads are most congested and the pressure on road space immense.
"When a parking profit is made the law states that, essentially, the money can only be spent on transport and environment projects. We are simply asking that all councils publish annual reports to tell drivers exactly where this huge excess ends up."
But the LGA's environment spokesman commented: "This is a wholly inaccurate and misleading report, which peddles the myth that councils make a profit from parking.
"The reality is, income is spent on running parking services and any surplus is only spent on essential transport projects, such as tackling the £12 billion roads repair backlog and creating new parking spaces.
"Councils are on the side of hard-pressed motorists. The average motorist is paying 30 times more to Whitehall in charges and taxation each year than they do to their town hall through parking."
Here is a list of the councils with the 10 largest parking surpluses, according to the RAC Foundation:
:: 1. Westminster £46.4 million
:: 2. Kensington and Chelsea £33 million
:: 3. Camden £24.5 million
:: 4. Hammersmith and Fulham £23.8 million
:: 5. Wandsworth £20.4 million
:: 6. Brighton and Hove £18.6 million
:: 7. Haringey £16.1 million
:: 8. Islington £13.7 million
:: 9. Nottingham City £13.3 million
:: 10. Hackney £10.8 million