More than 50 police officers will be patrolling the three-day Climate Camp, due to kick off tomorrow.

Chief Inspector Graeme Donnelly, of Wollongong police, said officers would maintain a high profile at the protest, aimed at stopping the expansion of the Metropolitan Colliery.

Protest organisers had sought permission to march through the main street of Helensburgh on Sunday, but Chief Insp Donnelly said negotiations over the route were continuing.

"We obviously have to take the public interest and safety into consideration before approving a route," he said.

The three-day camp includes workshops and demonstrations that organisers say are aimed at protecting water catchments from damage and pollution by coal mining.

At the inaugural Australian Climate Camp in Newcastle last year, six activists were arrested for blocking a coal train.

A spokeswoman for mine owner Peabody Energy said operations would continue as normal this weekend but no trucks or trains would operate to or from the mine on Sunday, the expected day of the march.

"We have been working very closely with the NSW police," she said.

She said there were hazardous areas within the mine's boundaries that required an induction process to enter normally, which could be particularly dangerous should protesters force their way in.

There are also buildings of heritage significance in the mine's boundaries, which officials are concerned about.

Private security will also be on hand to protect the boundary and core assets, the Mercury has been told.

Employees are expected to travel to work as normal.

The Climate Camp website promotes Sunday's march as "peaceful".

"Please wear blue and be creative with our theme of water, climate and jobs.

"Join hundreds of parents, youths, locals and workers in a community rally and peaceful walk-on to the site of Australia's oldest coalmine in Helensburgh."

Last week, Wollongong local area commander Superintendent Kyle Stewart warned protesters heading to the camp to stay within the law or they would face arrest.