Officers on jet-skis will patrol the Tyne

The policing operation for the Labour Spring Conference at The Sage Gateshead is expected to cost �2.8m with 1,600 officers involved in total.

Armed roadblocks are already being carried out ahead of the three-day event, which starts on Friday.

The Army is helping Northumbria Police with preparations and specialists from other forces have advised.

The massive security operation will take in an area around the Sage and Hilton hotel and roads will be closed.

The Swing Bridge, the only bridge which will be completely closed will be shut from 2200 GMT on Thursday. The Tyne Bridge will be closed to pedestrians, but a free shuttle bus will operate.

There will be no river traffic from Ouseburn to Dunston Staithes from Thursday evening to Sunday evening. Officers on jet-skis will patrol the Tyne.

The event will be one of the largest the force has dealt with

Armed officers have been operating roadblocks on routes into Newcastle and Gateshead using powers under Section 44 of the Terrorism Act.

By Monday morning, 170 people had been stopped, with four arrests in relation to criminal-related matters.

Police say there is no specific intelligence to suggest the conference will be a target for terrorists but they will remain vigilant.

Asst Chief Constable David Warcup said they had been speaking to about six groups about protests they wanted to hold over the weekend.

Protests will be centred across the river from the Sage and some will be allowed to go over to the Sage by prior agreement.

He said despite the massive operation, which will mean 1,000 officers on duty at any one time, policing across the rest of the region would not be disrupted.

He said the force had applied to the Home Office for help with the costs of the operation and was hopeful it would get a "considerable contribution".

Mr Warcup said six months' planning had gone into the operation and the force recognised the importance to Tyneside's profile in hosting the conference.

He said: "I think it's a professional challenge that we will look forward to."