Armed police will check every vehicle being driven into the heart of Brighton to try to prevent terrorist attacks during the Labour Party Conference.

Residents or businesses wanting to drive near the Brighton Centre will have to apply for special passes to get access.

Officers will check vehicles entering the area and will refuse entry to those not having the correct pass.

Any vehicles left parked in the area without a pass on show will also be removed.

With just over six weeks to go before the conference begins at the Brighton Centre, Sussex Police has highlighted legitimate parking in the already overcrowded city centre as a major concern.

Under the terms of Operation Otter residents and businesses who have Zone Z permits and would normally have access to the area surrounding the conference centre will be able to apply for a vehicle pass allowing them to drive in and out.

A dedicated counter terrorism team based at John Street police station has marked out an ‘Island Site’ - an area including the Brighton Centre, the De Vere Grand Hotel, the Russell Road car park and the Hilton Brighton Metropole Hotel - as a high risk zone.

With politicians including Prime Minister Gordon Brown coming and going armed police will guard the area from Sunday September 27 until Thursday October 1.

Only vehicles with the special pass will be allowed entry and residents who require parking in Queensbury Mews are also advised to visit the Sussex Police website as there will be restrictions alongside the Hilton Metropole Hotel. Shoppers will still be able to use the area outside the zone without needing a pass.

Barriers will be put up the week before the conference and Kings Road may have to be closed at times while police deal with demonstrations. But officers say they will publicise any closures and diversions as early as they can.

Around 1000 officers have been deployed for Operation Otter which has cost the Home Office £5.7 million and is the biggest operation undertaken by Sussex Police.

The shops at Churchill Square will remain open as normal.

The only car park closed to normal access is the Russell Road NCP site.

The Churchill Square car park will be open but drivers will be searched on their way in.

Superintendent Grenville Wilson, who is running the operation for the force, said: "We are holding meetings with local residents and businesses in the coming weeks and sending out regular newsletters to keep the city's residents, businesses and visitors fully informed as to how the security arrangements may affect them during the conference."

The conference is predicted to pump around £10 million into the city's economy this year and attract around 20,000 delegates.

Anyone who wants more information should email otter.vehicles@sussex.pnn.police.uk for help.

For Operation Otter updates on the Sussex Police website visit www.sussex.police.uk/otter2009.