Adam Bandt, the leader of the Australian Greens, and Sue Higginson, the NSW Legislative Council member, were on Horseshoe Beach in Newcastle on Saturday morning as protestors sailed into the mouth of the harbour, beginning a rolling blockade.
Mr Bandt, who paddled out among the protesters as the flotilla of rafts and kayaks launched around 10am, came ashore to lambast the federal Labor government after it approved a new coal mine in May.
Protesters at the weekend demanded a stop to new coal and fossil fuel extractive projects, and the introduction of "a 75 per cent federal tax on fossil fuel export profits to pay for community and industrial transition, and climate loss and damage overseas" and vowed to blockade the harbour for 30 hours.
The Port of Newcastle stopped all ship movements for the duration of the authorised protest action, citing safety concerns for the number of people in the shipping lane. It said all vessels were at a standstill regardless of their cargo.
The statement from the port followed claims by the protesters, led by Rising Tide, that the action had effectively stopped as many as eight ships carrying an estimated half a million tonnes of coal.
"These people are fighting for fewer bushfires, fewer floods and fewer droughts in our country to ensure that our kids and our grandkids get to enjoy this country in the same way that previous generations have done," Mr Bandt said.
"Coal and gas are fuelling the climate crisis, and in the middle of a climate crisis, Labor is making the problem worse by opening more coal and gas mines.
"You can't put a fire out while you're pouring petrol on it. And people here have a very clear message to Labor to stop opening new coal and gas mines."
Policy think tank The Australia Institute has tracked four new or expanded coal mining operations that have gained approval since May 2022, when Labor took office.
Earlier this week, the Albanese government declared it would expand a taxpayer-underwritten scheme to support new clean energy generation and storage to meet its renewable energy targets by 2030.
The package, announced by Energy Minister Chris Bowen on Thursday, builds on pilot arrangements in NSW, Victoria and South Australia and is intended to share the risk of building new assets and avoid price spikes for consumers.
Ms Higginson said the state government was considering its own climate bill but "doesn't talk about the 14 new coal projects currently in the pipeline".
"The 14 new coal projects to add to the existing 40 coal mines in this state that is literally fuelling the world's climate crisis," she said.
"We are sending coal out of this port every day of the year except for this day and except for tomorrow.
"This is the beginning of the end of coal."
Rising Tide representative Alexa Stuart said the weekend's protest represented the largest climate-related civil disobedience in Australian history, adding that thousands of protesters had come to participate in the blockade.