The small army of traffic wardens patrolling inner London numbers one third of the entire police force deployed to keep the area safe.
Some 900 wardens patrol the 13 inner London boroughs - compared with 2,989 police on the beat on the average day.
The Taxpayers' Alliance said: "Taxpayers would rather more money was spent on catching criminals than fining people for petty parking offences."
But parking operator NSL Services said they provide a "vital service."
The numbers were released to the BBC after a Freedom of Information request.
Matthew Elliott, of the Taxpayers' Alliance, said: "If the proportion of police to traffic wardens is this out of kilter in central London - where so many police are deployed to protect key government buildings - it must be even worse elsewhere."
He continued: "I find it very surprising. People would expect traffic wardens to be equivalent to about 10% of the police force at most."
Mr Elliott was echoed by parking campaigner Neil Herron who said: "With all the police protecting Parliament and other strategic buildings there will effectively be more wardens on the street than coppers.
"It can't be right.
"This shows the system is out of balance, out of control and needs to be completely overhauled.
"We have to stand up and say 'we have had enough'."
But not all agreed.
A London Councils spokeswoman said: "Parking enforcement is carried out to keep London moving, to maintain the safety of all road users and to ensure limited parking space is available for those who need it."
Tim Cowan, of NSL Services - formerly NCP Parking - said: "This demonstrates why decriminalised parking enforcement is the best way to manage parking.
"We provide a vital public service."