The rescue package will save about 6000 jobs that depend on the aluminium smelter, but critics fear it may end up costing taxpayers even more.

Prime Minister Anthony Albanese and NSW Premier Chris Minns are expected to travel to Tomago just outside Newcastle to announce the deal on Thursday.

Anthony Albanese and NSW Premier Chris Minns are poised to sign a bailout agreement for the beleaguered Tomago aluminium smelter, ending months of uncertainty for workers.