Brighton residents are urged to become the eyes and ears of the police in a bid to fight terrorism in the run-up to the Labour Party conference.

More than 3,000 people will have to go through checkpoints to get to their homes during the five-day conference next month.

Police want residents to look out for suspicious packages and people in the town before the conference, which starts on September 24.

Superintendent Mark Streater, security planning co-ordinator, said: "We are asking for people to be particularly attentive to suspicious activity and people so we have thousands of ears and eyes out on the ground and can ensure Brighton doesn't become a target as it did in 1984.

"Overall the threat to the mainland from Irish terrorism is considered high and is looking to remain so for the remainder of the summer."

The conference site itself will become an isolated zone surrounded by a 6ft fence days before delegates arrive.

It will enclose the Brighton Centre, Grand Hotel and Metropole Hotel, which are to be linked by a "bridge" erected solely for the duration of the conference.

Hundreds of hotel workers are to be vetted and the area searched before the "island site" is sealed off to the public.

Supt Streater said: "It will become a sterile area which will be searched in some detail, with the assistance of the military, and we will make sure there is nothing within the area that could cause anybody any harm."

Residents living in Metropole Court will be included in the island site and Brighton and Hove Council and police have held several meetings with residents to keep disruption to a minimum.

Plans begin in earnest on September 12, when the connecting bridge is put in place. The isolation zone will be sealed on September 22, but the only road to be closed to the public will be the southbound route in Cannon Place.

The Sussex Police helicopter has been provided with photographic equipment to relay aerial pictures to officers on the ground and an underwater unit will be on standby to intercept suspicious vessels at sea.

An Islander aircraft will also be on standby in Hampshire, if needed, with an air exclusion zone over the conference site.

A giant air shelter is being erected to search HGVs and lorries delivering to the hotels and vehicle checkpoints will be set up around the town and at the nearby Churchill Square car park.

Additional officers from the Metropolitan, Hampshire and Kent forces are on stand by to be drafted in at a moment's notice.

Several organisations have informed police they intend to stage demonstrations during the conference.

Most organisations have liaised with police about lawful protest but the anti-capitalists have so far refused to co-operate.

Supt Streater said: "It concerns me that any group would want to come to Brighton when it's so busy and not seek to work with the police to ensure we can look after their safety and, more importantly, other people in Brighton."