The museum would grow exhibition space, create room for functions, events and large displays, and improve the path through the building for visitors under the project.

A committee of MPs found the redevelopment should go ahead and recommended backing for the project, which is part of a larger museum plan to double exhibition space and raise more income.

Permanent galleries would become three distinct spaces "with a linked narrative experience that comprehensively tells the story of Australia" under the gallery renewal plan, the museum told MPs.

In the first phase of the plan, which received the committee's backing, the National Museum would redevelop original exhibitions and create a new 1500 square metre permanent exhibition of environmental history.

Museum officials told MPs the galleries are showing "significant signs of age" after 20 years and would not meet the demand of growing visitor numbers. Visitor numbers grew from 600,000 in 2014 to more than 1,000,000 in 2018.

"With increased visitation forecast to continue, addressing the age and deficiencies of current galleries is an urgent priority," the museum said.