Dozens of protesters have locked themselves inside Bill Shorten's Melbourne office to protest against Adani's Queensland Carmichael coal mine.
The Galilee Blockade protesters entered the Moonee Ponds office moments after the opposition was seen leaving on Thursday.
Protester Michael Staindl said the Labor opposition was taking a "low profile" and "sitting on the fence" on the controversial mine project.
"We need them (Labor) to take a much stronger stance on this," the 64-year-old said.
He said the people of Queensland had been misled by the promise of jobs, which would instead cost coal jobs elsewhere in Australia.
The businessman said he was happy to risk arrest to protest against the coal mine.
"Ten years ago, I'd have never done something like this, but it's important and we need to focus on renewables not fossil fuels," he said.
Bill Shorten's office has been contacted for comment.
Police and security staff were in the office but did not disrupt the peaceful protest.