Scott Morrison has denied his environment minister is sitting on approvals for the Adani coal mine in Queensland as opposing forces within his government are once again at loggerheads over the project.

A delegation of Queensland MPs reportedly met with the prime minister on Thursday to express their concerns that federal approval for the massive Galilee Basin mine had not been signed off despite being rubber-stamped by the environment department.

Environment Minister Melissa Price had refused to issue the approval after intense lobbying from southern state Liberals concerned about public sentiment against the mine, The Australian reported.

Mr Morrison on Friday said that was just “excited reporting” and normal processes were being followed.

“There has been no delay,” he told reporters in Canberra.

“This is one of a large number of approvals. This is actually a sub-approval to a previous approval.

“We will make sure that in providing any of the consents that are required under the (environmental protection) act that they’re done properly with the fullest of information.”

Energy Minister Angus Taylor – who is not in charge of the environmental approval process – said the government needed to make sure it was done as quickly as possible.

There were reports Resources Minister Matt Canavan – a Queensland Nationals senator – had threatened to quit cabinet over the dispute on the eve of the election, but he says that is incorrect.

Labor said the apparent heavying of the minister by both supporters and opponents of the mine was yet another sign of the division within the coalition.

“We can’t have significant environmental decisions made at the whim of the infighting of the government,” Opposition Leader Bill Shorten told reporters in Canberra.

The Indian mining giant’s planned $16.5 billion project has become a symbol of the battle over action on climate change.

Adani plans to start producing around 10 million tonnes of coal a year and eventually ramp up to 27.5 million tonnes at the mine.

Environmental groups have slammed the proposal, which they say was not properly assessed and puts water resources at risk.