Retailers may be forced to pass on a new “shopping tax” to customers under new plans by local authorities to charge for parking spaces.

Supermarkets, department stores and shopping centres would be charged £600 per parking space under the new scheme, generating millions of pounds for councils.

Councils hope the scheme may encourage people to walk or use public transport, as opposed to their cars.

According to the Daily Telegraph, at least one supermarket is planning to pass on the parking fees directly to customers, by listing it as a separate tax on till receipts, or by passing on the tax through higher prices or a direct car park charge.

Sources told the newspaper the tax could come into force next year.

Councils including Exeter City Council are backing the tax. Under its plans, retailers would be taxed less if they could prove they had sourced “at least 30% of goods from within 30 miles” of the town.

Shadow communities and local government secretary Caroline Spelman said: “Ministers are off their trolley if they think that there will be any public support for these plans, and Conservatives will oppose such taxes every step of the way.”

However sources said Communities and Local Government Secretary John Denham was “likely to rule out tax-raising proposals”.