Lawyers assisting the Victorian Bushfires Royal Commission have slammed police, fire authorities and official policy in new submissions to be lodged with the inquiry this week.

A submission leaked to The Sunday Age before it was officially presented to the royal commission criticises the authorities for “substantial policy failure” in the wake of Black Saturday, including a failure to recognise the “stay or go” policy has since been discredited.

“The existing policy should be abandoned,” they say, adding it placed at least some of those who died “at great risk”.

Of the 173 people who died in the disaster, 113 died in their homes while a further 11 died seeking refuge.

Fire authorities have since toned down the implication that the family home can be a relatively safe refuge, pointing to evacuation as the safer alternative.

The team of lawyers, led by Jack Rush QC, are now calling for the introduction of voluntary evacuation as the primary response to bushfires, with officially designated shelters regarded as the next best option.

In another submission, they have slammed the upper management levels of the police and fire authorities, noting a “lamentable lack of responsibility and leadership from the most senior personnel involved in the response to the unfolding disaster”.

They also call for a new authority structure that hands full control to the Country Fire Authority Chief Officer when a bushfire strikes.

Counsel are also critical of the Victorian Government’s slow progress in identifying and building official shelters, calling for a massive increase to the 73 existing shelters by next bushfire season.

The royal commissioners are due to release a final report on July 31. In a media release issued this morning, Chairman Bernard Teague criticised “internal sources” for leaking the submissions to the general media. The submissions were distributed in advance to all parties appearing at the royal commission.

Hearings will conclude next week.