The Greens will launch a fresh assault on the Labor Party over Adani's Carmichael coal mine on Saturday, mounting a door-knocking campaign in some of the opposition's most marginal, inner-city seats in an effort to force their hand on the potentially toxic issue.

More than 100 campaigners - including Greens leader Richard Di Natale and climate change and energy spokesman Adam Bandt - are expected to descend on the inner suburbs of Melbourne. They will target three marginal Labor seats, Peter Khalil's Wills, Michael Danby's Melbourne Ports and David Feeney's Batman, as well Mr Bandt's own electorate of Melbourne.

The Greens are on the brink of seizing the inner Melbourne seats from Labor, and they wants the federal opposition to commit to opposing the $22 billion Queensland project. While Opposition Leader Bill Shorten has expressed support for the mine if it "stacks up", several MPs and climate change and energy spokesman Mark Butler have hit out at the project.