A man who told Tauranga ACC staff 'I will come and blow you all away”, following the murder of two Work and Income employees in Ashburton, will be sentenced next month.

Hamilton man Darren Old, 44, pleaded guilty to threatening to shoot ACC staff when he appeared in Hamilton District Court today.

Fairfax media reports Old was charged after police declared a zero-tolerance stance against anyone who threatened government workers.

Old was seeking a lawyer to help him seek compensation from ACC for an old back injury when he told staff: "I should get a shotgun, did you see what happened in Ashburton?"

The court heard ACC had arranged for Old to attend a specialist's appointment to assess his condition, but he cancelled it.

It was when ACC got back in touch with Old on September 6 to question him when he became angry and threatened to shoot staff.

Old admitted making the call and told police that he was angry and frustrated at the time and had no intention of following the threat through.

The threat came five days after the horror shooting on September 1 where Peggy Noble, 67, and Leigh Cleveland, 55, were shot in the town's WINZ office.

Ashburton man Russell John Tully, 48, has been charged with their murder, and attempting to murder a third victim, Lindy Curtis.

Old was remanded on bail for sentencing next month in the Hamilton District Court.