The Ministry of Social Development has pleaded not guilty to failing to keep its employees safe at work after a shooting in Ashburton led to the deaths of two staff and injuring of two others.

WorkSafe NZ laid one charge against the Ministry of Social Development (MSD) after the shooting on September 1 last year.

WorkSafe NZ alleges the MSD failed to take all practicable steps to ensure the safety of its employees while at work.

The charge, under section 6 of the Health and Safety in Employment Act, was laid in Wellington District Court.

The Ministry's lawyer Brent Stanaway told Judge Peter Hobbs that a hearing of up to two weeks could be needed. He asked for a case review hearing.

The judge remanded the case until August for another preliminary hearing.

Russell John Tully, 48, has been charged with the murders of Peg Noble and Susan Leigh Cleveland, and seriously wounding Lindy Curtis, at their Cass St office

Another staff member, Kim Adams, was shot at as she ran out the back door. A date for Tully's trial has not yet been set.