Bill Shorten has distanced himself from Labor's climate change spokesman's comments about Adani's proposed Carmichael coal mine.
Mark Butler made his thoughts clears about what should happen to the Galilee Basin in Queensland in a video posted to social media on Friday.
"I do not support opening new mines in the Galilee Basin, whether it's by Adani, Clive Palmer or anyone else for that matter. It just doesn't make sense," Mr Butler said.
The opposition leader says there is still plenty of scepticism that the controversial project will ever go ahead, with Adani this week ditching plans to build a new rail line and opting for a cut-price solution.
The move comes in an attempt to get the mega-mine approved and to convince banks to lend to the project.
Australia's big four banks have refused to put up money, forcing the company to look for funding overseas as environmental groups call on government to stop the project in its tracks.
"I think that that is essentially Mark's judgement, that he doesn't think it is going to happen and he doesn't support it," Mr Shorten told ABC's Insiders on Sunday.
"Our policy is that we won't put a single taxpayer dollar into the project.
"I think that a lot of people think that despite all the press releases coming out of Adani, there's more hype than substance.
"If and when we're elected, and that's a big if, of course, we have to get elected, I'll sit down with my cabinet colleagues - we will work on the best science available."
Resources Minister Matt Canavan has been a staunch defender of the proposed mine and has criticised Mr Shorten's "continued fence sitting".
"How can a shadow minister have a 'judgement' about such an important project, and the opposition not have a view at all?" Mr Canavan said on Sunday.
"Queensland workers deserve to know what Labor's position is - otherwise they would have to conclude that Labor just cannot be trusted."
