Thousands of people took to the streets of Batemans Bay on Saturday to protest about the State Government's approval of a controversial charcoal plant for the Eurobodalla.

The protesters stopped traffic on the Princes Highway as they vented their anger at the Carr Government.

Carrying placards and chanting, the protesters marched through the main street of Batemans Bay, across the highway and onto a football oval for the rally, which attracted people from all political persuasions.

Police estimated more than 3,000 people turned out to voice their disgust at the idea of a charcoal plant being built in an area which promotes itself as the Nature Coast.

NSW Opposition leader John Brogden addressed the rally, promising the Mogo plant would not go ahead if a Coalition government was elected next March.

Wilderness Society spokesman Glen Klatovsky said the anti-charcoal movement is the most incredible community campaign he has ever seen, and claims it is winning the battle against Australian Silicon's proposal.