Householders living near a supermarket in Longwell Green are fighting plans for a new car park they say will be almost the same height as their homes.

Asda wants to extend its sales floor and provide a decked parking area above existing car spaces.

It said the extension was needed to provide more room for its George clothing range and other non-food items, while the decked car park would provide 101 extra spaces for customers.

It is also planning a cafe on a mezzanine floor within the store.

But neighbours said they felt the store had reached its capacity and further expansion would be to the detriment of local families.

They were especially concerned about the car park, which they said would have a major impact on nearby houses, and how the roads would cope with extra traffic.

Patricia and Barry Clark, of Craven Close, are among more than 240 people who have written to South Gloucestershire Council opposing the plan.

There are also 260 signatures on a petition that will be presented to the planning committee.

Oldland Parish Council has also objected.

Mrs Clark said: "This is primarily a residential area and we hope that will be taken into account when the application is considered.

"The proposed decked car park will have a tremendous effect. It will be on stilts and will only be about a metre lower than the height of the houses.

"We're not knocking Asda for being there. We've lived here for about 12 years and the store has been here for longer. Many people are grateful to have a supermarket but I think it's now reached its limit.

"The primary concern among people around here is the effect it will have on roads. There is already congestion and this will create extra traffic. We want to know if Asda really needs extra car parking space."

Opponents said lighting and the noise of cars using the new parking area would cause problems and they were worried youngsters who already "screech" around the car park at night – the store is open 24 hours a day – would do the same on the decked parking area and ramp.

Neighbour Jenny Taylor said: "The traffic around here is terrible already and this will make it worse. I moved to this house knowing Asda was here but I think it is now big enough."

Chris Marlow, Asda's property spokesman, said: "The plans for our Longwell Green store are designed to deal with the existing problems, identified by the council, of congestion and parking as well as offering customers a wider range of products and a cafe.

"The plans will also create up to 60 new jobs for local people.

"We are making special efforts to deal with anti-social behaviour as part of the application, working closely with police and installing CCTV."

He said road layout changes were planned to help ease congestion and measures to minimise any impact on residents included a solid railing along the deck edge facing Craven Way and special lighting.

Mr Marlow said: "The car park will be lower in height than the houses and also lower than the store."