Mr Brown said the convoy had the potential to dwarf the campaign by environment groups to stop the damming of the Franklin River in the 1980s. The Hawke Labor government's election in March 1983 resulted in Canberra intervening to stop support for the dam after Mr Brown helped lead a blockade on work from the preceding December.

"It's extraordinary - I haven't seen such a reaction," Mr Brown said, of opposition to the Adani mine.

Adani Mining said some 14,500 people had registered to work for the mine, most from Queensland.

“We ask activists from interstate to respect the thousands of people across regional Queensland who want the Carmichael Project to proceed because they need a job and understand the contribution that mining makes to both the state and national economy," a spokeswoman said.

“After more than eight years of rigorous scientific assessment, regulatory approvals and legal reviews, the community can be confident that the project stacks up environmentally."

The Indian-owned company is "conducting stage 1 work" as it prepares to develop a mine with an annual coal output of 10-15 million tonnes, the spokeswoman said.

This work involves road surfacing and grid, fencing and signage, she said.

'Litmus test'

Plans for the convoy come as independents running in blue-ribbon Liberal seats have spoken out against the mine.

Oliver Yates, who is running against Treasurer Josh Frydenberg has made known his opposition to the planned coal mine, while Zali Steggall has told the Guardian that Labor was not "ambitious enough" and should make an explicit commitment to block Adani.

"Adani will be a litmus test," Mr Brown said. "Both big parties support this mine."

According to Mr Brown, some 6000 people eventually joined the blockade against a dam on the Franklin River, with 500 of them arrested.

The organisers, including the Frontline Action on Coal, plan a series of public events along the convoy's path.