“The best way to make sure everything runs well is to open the tunnel and run the services first and then make the big timetable switch,” she said.

Allan announced the opening period on Tuesday morning, the third straight day of drip-feeding information about the completion of her government’s flagship infrastructure project.

The Andrews Labor government first announced the nine-kilometre cross-city rail tunnel in 2015. It will join the Sunbury and Pakenham/Cranbourne lines with stops at five new inner-city underground stations.

Allan and transport minister Gabrielle Williams announced over the weekend that major construction was completed on the two CBD stations: Town Hall, which connects to Flinders Street, and State Library, which connects to Melbourne Central.

Start the day with a summary of the day’s most important and interesting stories, analysis and insights. Sign up for our Morning Edition newsletter.