Only half the number of Abingdon residents who pay £100 a year for a car parking space are guaranteed a bay outside their home.

A total of 102 households in the town have signed up to the residents' parking scheme, but there are just 52 spaces designated for their sole use.

There are 75 pay and display spaces in the town centre, which can also be used, but residents have complained these are always taken up by those not part of the scheme.

Hector Mackenzie, 50, has been part of the residents' parking scheme in West St Helen Street for four years.

He said: "It's totally impossible. If you get back after six or seven o'clock in the evening, you never get a space.

"It's incredibly annoying. One night I parked my car in the car park and I forgot to move it first thing in the morning, and got fined £50.

"I pay £100 a year. You would have thought they would have some flexibility in the car parks when the on-street spaces are full."

Scheme member Liz Lafon , 57, said: "It's really unfortunate, especially when Oxford residents moan about paying £50 a year."

Parking spaces have been removed from Bridge Street, following the installation of traffic lights, and in West St Helen Street. Further spaces along Bridge Street will be lost once the Old Gaol development begins.

Five parking bays are also out of use in West St Helen Street because of building work at the Co-op.

Lesley Legge, leader of the town council, said: "There has been increasing pressure on the system. It has been suffering with a lack of number of spaces for the past decade."

As part of consultation by Oxfordshire County Council in 2004, which came up with the Abingdon Integrated Traffic Strategy (Abits), alternative car parking spaces were looked at. But because of a lack of funding, the idea was not pursued.

The town council hopes to meet county council officers to look again at this idea.

Town councillor Julie Mayhew-Archer said: "This has been a problem for some months, and it urgently needs addressing. We asked the county council more than three years ago to increase the parking spaces.

"It is £100 a year for residents' parking, which is the most in Oxfordshire. People are happy to do that if they can come home and park, but they are not happy that they cannot do this."

Transport Planner Cathy Browning said: "There are some difficulties. However it is desirable for us to create more bays and we want to concentrate on finding ways to deliver that."