One of the state's biggest unions has called on the McGowan government to follow a Victorian Labor party commitment and introduce 20-year jail sentences and multi-million-dollar fines for employers who fail to prevent workplace deaths.

On Saturday Victorian Premier Daniel Andrews announced they would introduce industrial manslaughter legislation if relected in November.

Gerard "Gerry" Bradley and Joe McDermott, from Northern Ireland, were killed in a workplace accident in East Perth in 2015. Credit:Facebook

The legislation would create criminal offences for workplace deaths, allowing employers to be fined almost $16 million for a death under their watch or jailed for up to 20 years.

Queensland introduced similar laws earlier this year.