Protesters have spent the night blockading the world’s largest coal port over what they say is the failure of government to act on climate change.

Several hundred protesters blocked Newcastle Port’s shipping lane on Saturday, remaining overnight and into Sunday with the action due to end at 4pm.

The group behind the protest, Rising Tide, claims over half a million tonnes of coal will be prevented from leaving the port for the duration of the action.

Protesters are demanding the government stop allowing new coal projects, tax fossil fuel export profits at 75 per cent to fund community and industrial transition, and pay for climate loss and damage.

Rising Tide community organiser and spokesperson Zack Schofield said safety was paramount as the protesters spent the night on the water, rostered in two hour shifts.

He said police had granted permission for the protest to take place following several months of negotiations with organisers.

Greens Leader Adam Bandt, who kayaked out with protesters on Saturday called those taking part heroes.

“They’re fighting to stop more floods and bushfires in this country,” Mr Bandt said

“People here know that we’re nearing a climate tipping point, and that coal and gas are fuelling the climate crisis.”

But NSW Minerals Council CEO Stephen Galilee said that while everyone had the right to protest, protest leaders had to ensure those participating did it safely and within the law.

He said stopping NSW coal exports would have a major impact on the NSW economy, with exports providing jobs for over 25,000 people in the state and indirectly supporting tens of thousands more.

“Coal is NSW’s most valuable export by far, and worth more than $70 billion nationally.”