The works will involve demolitions and rebuilds to improve accessibility at the heritage Lydiard Street theatre.

This is the second time council has sought to begin works, with tenders initially advertised in July 2020 just before the second wave of the pandemic struck.

This time, the expressions of interest period will be open until October 20, with tenders to be advertised in January 2022 before contract work begins in April.

The contract is expected to be complete in July 2023, according to council documents.

The upgrade would include demolition and reconstruction of the north fire stair and stalls fire stair, and the supply and installation of new lifts at the front of house and back of house.

It would also include refurbishment of the front of house and administration areas, upgrades to fire detection and protection systems, and accessibility compliance upgrades.

Providing full accessibility in the theatre, for both audience and performers, has been a priority since stage two rehabilitation works were completed in 2019 - already, at least one show has been forced to move to council's Civic Hall because of the lack of compliance.

"With stage one and two works now complete the next stage of works will continue the intent to improve necessary access, compliance upgrades and improve the overall operational functionality, ensuring the survival of one of Australia's most historic theatrical assets," council documents state.

Her Majesty's Theatre is understood to be the oldest mainland theatre still in operation - it was opened in 1875 with a performance of the comic opera La Fille de Madame Angot.

Have you signed up to The Courier's variety of news emails? You can register below and make sure you are up to date with everything that's happening in Ballarat.