A secure 'Island Site' will surround the Brighton Centre for six days

Section 44 of the Terrorism Act 2000 will allow them to search people within a specified area, without having grounds for suspicion.

Sussex Police said the use of the power would be closely monitored, with local advisory groups and racial harassment forums consulted.

The conference runs from 25 to 29 September at the Brighton Centre.

Police working on Operation Otter have so far said there was no indication of any specific threat to the conference.

'Terrorism deterrent'

The S44 powers permit stop and search "without the officer requiring grounds to suspect any offence taking place".

Assistant Chief Constable Geoff Williams said: "Sussex Police acknowledges the wide ranging extent of this power and... it is kept under constant review to ensure its use is necessary.

"The power is brought in as a deterrent to and a means of detecting anyone engaged in activities connected with terrorism.

"Each stop, whether or not this results in a search, will be recorded and officers have explanatory leaflets to pass on to those members of the public who have been stopped under the power."