Elderly residents who do not own cars are being overcharged for visitors permits, according to campaigners.

Merton residents currently pay a flat fee of £140 for an annual visitor’s permit, while the cost of a residents' permit rises with the number purchased from £65 for the first, £110 for the second and £140 for a third.

The system means that residents who don’t own a car, but who might need regular visitors, are paying double what a resident would to park in their road on an occasional basis.

Booklets of ten half and full day visitor permits are also available at £2.50 and £1.50 per permit, which are only cost effective if requiring up to 55 full day permits or 95 half day permits per year.

In 2012, 1,550 annual visitor permits were issued across Merton - 542 to residents without any other type of permit.

Anthony Fairclough, resident and Liberal Democrat campaigner, said: "Many people who don't have cars are older people, some of whom are reliant on regular visits from friends and relatives so the flat cost of £140 for an annual visitors' parking permit really hits them - a first residents' parking permit for a car owner costs £65.

"We hope that the council will listen and consider a fairer scheme, where the cost you pay for parking permits is linked to the number of permits you have in total.

"If you don't have a car, an annual visitors' permit should cost you the same as a residents' permit would."

A petition has already attracted 500 signatures with campaigners calling on the council's scrutiny panel to investigate.

Responding to calls for a review, Councillor Mark Betteridge, cabinet member for performance and implementation and deputy leader, said: "Our commitment to keeping Merton affordable has delivered significant reductions in the cost of half day visitors permits from £2.50 to £1.50.

"This is alongside freezing the cost of resident parking permits for the last three years.

"The annual visitor permit differs from the annual resident permit as it is not specific to any one vehicle and for this reason its cost has been priced to deter any wrong use."