Conservationists have been given more time to challenge any plan to dump Great Barrier Reef dredge spoil on land.

Green groups have won more time to legally challenge plans to dump dredge spoil from the Great Barrier Reef Marine Park on land.

The federal government last year approved of a plan to have three million cubic metres of spoil dumped in the marine park boundaries in north Queensland.

But following a public backlash, Queensland Premier Campbell Newman this month announced that his cabinet was instead backing a plan to have the material disposed of on land.

Conservationists, however, remain opposed to any dredging which would enable the expansion of the Abbot Point coal terminal, near Bowen.

They argue that dumping the spoil onshore would also damage a wetland which is home to threatened species.

On Thursday, the Mackay Conservation Group won more time in the Federal Court in Brisbane to appeal any possible proposal, which the state government is yet to outline.

The group was due to go to court at the end of October.

But they argued they needed more time to see the North Queensland Bulk Port Corporation’s alternative plan for onshore dumping.

“They weren’t able to say when the application will be made or by whom – whether it will be them or the Queensland government,” co-ordinator Ellen Roberts told AAP.

“We’ve seen a lot of speculation in the media, but no concrete application as yet.”

A ports corporation spokeswoman declined to comment while Deputy Premier Jeff Seeney’s office was unable to confirm when more details of the onshore dumping plan would be released.

Meanwhile, the federal government has this week signed off on a 300km rail line linking the Carmichael Galilee Basin mine to the Abbot Point terminal.

Mr Seeney later said he had offered the Mackay Conservation Group a briefing with him next week, to take its members through details of the onshore dumping plan.

“The details of the concept for the Abbot Point Beneficial Reuse Strategy was launched last Wednesday in Bowen in front of 700 people at a public meeting,” he said in a written statement.

“The formal (strategy’s) documents are due to be submitted to Commonwealth Environment Minister Greg Hunt next week.”

Mr Seeney said the plan would be made available after the documents had been supplied to Mr Hunt.