The station platforms were constructed using mining methods. Each platform is an individual tunnel, and are linked to the other platform in the same level by a number of cross tunnels. This choice in design left the remaining pillar of rock between the tunnels too weak to support the required loads, so it was replaced with concrete. A pilot tunnel was made, enabling the walls to be constructed ahead of the main excavation. The booking hall to the south was constructed 'upside down', with the support columns dug with augers from ground level, then filled with concrete. The roof was then constructed over these piles from ground level during a series of staged road closures, and once this was completed the excavation of the booking hall could be carried out underneath, while road traffic continued overhead. During construction, the Parliament House fence had to be removed, stored then re-erected. The station opened on 22 January 1983. At the time of opening the station had the longest escalators in the southern hemisphere. In 2025, the Pakenham, Cranbourne and Sunburyrailway lines will cease to stop at Parliament Station when the Metro Tunnel is due to open.
Facilities
Parliament station has three underground levels. It has a concourse level and four platforms on the two levels underneath. Each platform serves a separate group of rail lines that leave the Loop and radiate out into the city's suburbs. Parliament has two separate concourses. They each have a ticket office, toilets and ticket operated gates.
The northern is located at the junction of Spring, Lonsdale and Nicholson Streets, and has three escalators and a lift going down to the platforms, as well has a lift and steps leading to street level.
The southern concourse is near the Spring and Collins Street intersection, and has four escalators descending to the platforms. There are three exits to ground level via steps: one to MacArthur Street, the other two exits on Spring Street, facing Bourke Street and near Collins Street.
Platforms & services
Platform 1 - Clifton Group
Mernda line: all stations and limited stops services to Mernda
Hurstbridge line: all stations and limited stops services to Hurstbridge
Platform 2 - Caulfield Group
Pakenham line: all stations and limited stops services to Pakenham
Cranbourne line: all stations and limited stops services to Cranbourne
Frankston line: all stations and limited stops services to Frankston
Sandringham line: weekend all stations services to Sandringham
Platform 3 - Northern Group
Craigieburn line: all stations services to Craigieburn
