Shadow attorney general Nick Goiran will introduce the amendment, which would give Attorney General Tony Buti unambiguous power to direct the coroner's office to begin an inquest into a death.
Margaret Hawke killed her children, aged 10, seven and four months, at their Port Hedland home in 2022. The children's grandmother, Dorothy Papertalk, has urged an inquest into their deaths. Former coroner Phil Urquhart denied that request in 2025.
The case returned to public attention after a series of reports by The Australian found multiple warnings to child protection workers in the Pilbara were not heeded in the lead-up to the murders.
Pressure has since mounted on the WA government to demand a coronial inquest, but Buti and Premier Roger Cook have maintained their hands are tied. Under the current act, the attorney general can only direct an inquest after a request has been denied if fresh evidence has emerged.
Goiran's amendment is intended to remove that limitation, giving the attorney general clear statutory power to direct the coroner's office to begin an inquest. The move comes as a related child protection probe in South Hedland continues.