ABORIGINAL traditional owners will oppose plans to expand the Ranger uranium mine in Kakadu unless the operating company improves its environmental record.

The Gundjeihmi Aboriginal Corporation released a statement on behalf of Mirarr traditional owners yesterday, condemning the ``poor environmental performance'' of Energy Resources of Australia, after it was revealed contaminated water had flowed from the mine into Kakadu between April 9 and April 11.

Mirarr traditional owners are calling on ERA to enter into a partnership to protect the world heritage-listed national park from environmental damage.