Coal operators have called for caution ahead of a scheduled Newcastle Harbour blockade climate activists are promoting as the "largest climate civil disobedience in Australian history".
Activists are preparing to travel from across Australia for four days of action that will culminate with a blockade of the harbour on Saturday November 25.
Hunter-based climate action group Rising Tide said it expected about 3000 people would participate in the event.
It will be the third time activists have blockaded the harbour in the past decade.
An estimated 2000 attended a May 2016 harbour blockade. A total of 66 people were arrested at various points around the port including at a large protest at the Kooragang rail line.
Senator David Pocock, Greens leader Adam Bandt and Sydney Lord Mayor Clover Moore are among those promoting this year's "People's Blockade" of the port.
"We must take out fossil fuels faster, fairly and forever. The decline of the fossil fuel industry is not happening fast enough. We need to act with the urgency that this moment demands. I support peaceful civil disobedience and protest and the People's Blockade of the world's largest coal port," Ms Moore said.
NSW Police and the Port of Newcastle declined to comment.
A spokesman for Port Waratah Coal Services said safety was always the company's top priority and cautioned anyone against entering into an environment where they were not trained to work in.
Senator Pocock told a recent Rising Tide forum in Canberra that non-violent direct action had played a vital role in bringing about social change in Australia.
"When you have a government that is making decisions, that mean that you cannot tell your kids, hand on heart, that they are going to be OK, then you look through history - there's been a long history of on nonviolent direct action to get people's attention, to stand up for all of our lives and our futures," he said.
"I would urge you to get involved. Talk to your friends and your family, see how you can help out and ensure that come November, there's a big crowd of people getting amongst it."
Rising Tide members recently completed a 5,000 km road trip of Australian cities to promote the event.
Climate disaster survivors, First Nations people, political leaders, academics, and Newcastle's former Young Citizen of the Year Alexa Stuart spoke at various points on the road trip.
"It's great to see real climate leadership from some of our elected representatives. It stands in stark contrast to the actions of our state and federal governments who continue the outrageous approvals of new coal and gas projects," Ms Stuart said.
The scheduled harbour blockade follows Rising Tide's four-day climate conference, which was held in Newcastle in April.
The event culminated when about 50 protestors stopped and boarded a coal train heading to the Kooragang coal terminal on Sunday April 17.
About 50 people were arrested and charged with various trespass-related offences.
Greens leader Adam Bandt said he hoped to be in attendance at the upcoming harbour blockade.
"We need nonviolent civil disobedience," he said.
"The types of civil disobedience that have been so crucial throughout history in securing change, from ending slavery to gaining women's suffrage, from workers' rights to civil rights."
"I hope to be there with Rising Tide in Newcastle in November, because they are everyday people trying to protect this country we love from worse fires, floods and droughts,"
