Sir John Stevens, commissioner of the Metropolitan Police, said: 'I am against a blanket use of speed cameras. They should be used in the right places, targeted to reduce accidents and deaths.
'Using the revenue from speeding tickets to raise money for the police is not what the law is there for. It is contrary to the independence of the police.'
His opinion contradicts the Government line put forward by transport minister John Spellar last week, when he announced that the introduction of around 6,000 more speed cameras would make the roads a safer place, with some of the revenue going back to the police force.
The Met Police also believes that the plan to lower the thresholds at which speed cameras capture their prey would lead to a 30% rise in convictions - as many as 60,000 more - with no apparent improvement in road safety.
At the moment, cameras are triggered at speeds that exceed 10% of the limit with 2mph added: 35mph in a 30mph, for example.