Unions and Members of Parliament alike are welcoming the lengthy sentence handed down to Russell John Tully, who killed two women when he stormed the Ashburton WINZ offices in September 2014.

MORE: Tully sentenced to life in jail

Tully was yesterday sentenced to life imprisonment and a 27-year non-parole period.

It is the second highest non-parole period ever handed down in New Zealand history.

Glenn Barclay, National Secretary of the Public Service Association, said the severity of the sentence reflects the severity of the crime.

"The effect of his actions on the victims' family and our members who worked in that office and on that whole community can't be underestimated," Barclay said. "I think our members will be felling relieved by the level of the sentence."

The Ministry of Social Development, and Minister Anne Tolley have both praised the length of sentence, because for the families and staff concerned it's been very traumatic and distressing.

"Two lives were lost and another woman's life has been totally disrupted and she'll be traumatised and carry that trauma for the rest of her life, so it's nice to know he's going to be behind bars for twenty-seven years," Tolley said.

Tully was found guilty in March of being the masked gunman who stormed the Ashburton Winz centre on September 1, 2014 and shot dead receptionist Peggy Noble, 67, from point blank range and three times shot case manager Susan Leigh Cleveland, 55, as she pleaded for her life.

The 50-year-old was also found guilty of attempting to murder case manager Kim Adams. He was found not guilty of attempting to murder case manager Lindy Curtis who was shot in the leg and badly injured hiding under a desk.