Former federal environment minister and Midnight Oil frontman Peter Garrett has welcomed the Northern Territory’s decision to make a temporary reservation order over the Jabiluka uranium mine site and called on his former Labor colleagues to go further and add it to Kakadu national park.

The Northern Territory government has issued a two-year order to prevent mining and exploration at Jabiluka, while a decision is pending on whether to grant the leaseholder a 10-year extension.

The reservation order under the NT Minerals Titles Act was gazetted on Wednesday and while in force it also prevents Energy Resources Australia (ERA) from applying for the grant of any mineral title over the land, which is the site of a large uranium deposit.

Garrett called for the territory and federal governments to confirm they will reject the ERA application and give the area heritage protection instead.

“Now for the final step after decades of waiting,” Garrett posted on social media site X on Wednesday. “C’wealth & NT please don’t renew existing lease, instead commit to Jabiluka going into Kakadu National Park.”

The order giving the area temporary reserve status will be reviewed within two years, if no decision is made by then. The Northern Territory government has issued a two-year order to prevent mining and exploration at Jabiluka, while a decision is pending on whether to grant the leaseholder a 10-year extension.

The reservation order will be reviewed every two years if the lease application remains unresolved.

The move is a preliminary win for the local traditional owners, the Mirrar people, and limits what ERA can do with the lease until the NT government resolves its extension application.

The NT can seek advice from the commonwealth government in making its determination but the lease decision will be made by the territory government.

The reservation order by the NT Department of Industry, Tourism and Trade, on behalf of the NT minister for mining, will take effect on the day the existing lease expires – 11 August – and remain for two years unless it is cancelled in the meantime.

That date falls 13 days before the NT election on 24 August and the reservation order potentially pushes a decision out beyond the poll.

Jabiluka is the site of one of the world’s biggest uranium deposits and ERA, which is majority owned by Rio Tinto, has held the mining lease since 1991. The mine is surrounded by Kakadu national park and the Mirrar people want the land incorporated into the park.

The granting of the original lease was hugely controversial at the time.

In the 1990s, the Mirrar people led a blockade of the mine site and applied persistent pressure to stop development.

Before the August lease expiry, ERA lodged an application in March to have it extended for a decade. ERA also operated the Ranger uranium mine, 250km east of Darwin, from 1981 until it was closed in 2021. It is now rehabilitating that land at an estimated cost of more than $2bn.

In lodging its extension application for Jabiluka, ERA argued that an extension was the best way to protect the mine site’s cultural heritage and highlighted the long-term agreement it had reached with the Mirrar people which affords them a veto right over future development. The company vowed to keep that in place if the lease was renewed.

But the Mirrar people have objected to the extension. The traditional owners have long said they do not want mining on the land.

In late 2022, when ERA commissioned a report which suggested they might reverse their opposition, the Gundjeihmi Aboriginal Corporation, which represents the Mirrar people, said generations had opposed mining and that would not change.

On Wednesday, a spokesperson for ERA described the reservation order as “an administrative measure” taken when leases are expiring.

“The NT government has advised it will have no effect on their consideration of the extension of the mining lease at Jabiluka,” the spokesperson said.

“The extension of ERA’s mining lease at Jabiluka is the best mechanism to protect the cultural heritage at Jabiluka. Under ERA’s agreement with the Mirarr Traditional Owners, which has been in place for almost 20 years, Jabiluka cannot be developed without their consent. This right of veto expires if the lease is not renewed.”

The Mirrar traditional owners welcomed the decision as providing certainty about the future and protecting the Jabiluka site from new mine proposals.

“Mirarr have always said we will never agree to mining at Jabiluka,” next-generation traditional owner Corben Mudjandi said on Wednesday. “This is sacred country and needs protection.”

The Australian Conservation Foundation said the decision to bestow special reserve status on the Jabiluka site was a fitting tribute to the Mirrar people’s long-running campaign, especially on World Environment Day.

“While very welcome, today’s development is not the final chapter in the Jabiluka uranium story and struggle,” ACF nuclear-free campaigner Dave Sweeney said.

“It is imperative now that the intent expressed in the special reserve declaration is matched in reality with no extension of the current Jabiluka mining lease.”