Environment Minister Tanya Plibersek has downplayed her department’s approval of an expansion of Santos’ Surat Basin project as routine and environmentally sound despite warnings from the Greens that it leaves the government’s “climate credibility in tatters”.

The approval, which is part of a long-anticipated incremental expansion of the Santos-owned GLNG gas export project, comes as negotiations with the minor party continue over a heavy industrial emissions-reduction policy known as the safeguard mechanism changes.