Traffic wardens will be banned from clamping illegally parked cars in all but the most serious cases, under government plans unveiled on Thursday.

Wheel clamps should only be used as a last resort for motorists who persistently break the rules or fail to pay parking fines, proposed new guidance says.

Ministers say council chiefs must not set wardens targets for raising revenue from parking fines or the number of issued tickets.

Wardens should release clamped cars within an hour of payment. They should only tow cars away when it would help keep traffic flowing.

Clamping and towing away at night should be "particularly discouraged" because of the inconvenience and potential danger for motorists.

Transport Secretary Ruth Kelly "strongly discourages the use of wheelclamping", according to the consultation paper. People have until Oct. 31 to give their views before ministers draw up their final guidance.

Transport Minister Rosie Winterton said she wanted the penalties for those who break the parking rules to be "fair and justified".

"There is a perception that motorists are often unfairly penalised by parking attendants who are only interested in issuing as many tickets as possible," she told the Times.

The new guidance will only apply to council wardens, not private contractors.

The RAC Foundation said wheel-clamping is a punishment "that rarely fits the crime".

"Clamping a car for over-staying on a meter makes no sense, as the parking place is then blocked for a longer period," said its Executive Director Edmund King. "Clamping is a crude activity which should have been outlawed at the time of Dick Turpin."