The Engineering, Printing and Manufacturing Union (EPMU) says it may lobby the Government to put an experienced health and safety expert on the panel of the Royal Commission into the Pike River tragedy.
Assistant national secretary Ged O'Connell told Morning Report the panel needs someone with expert knowledge.
Mr O'Connell says the lawyer, trade unionist and ACC leader Ross Wilson should be added to the inquiry.
He says the union may go back to the families of the 29 workers to discuss the issue and then approach the Government to make an addition to the Commission's panel.