SUBURBAN RAIL LOOP - MOMENTS THAT MATTERED SO FAR:
* August 28, 2018 - Victorian premier Daniel Andrews announces plan to build Suburban Rail Loop, which transport infrastructure minister Jacinta Allan says will cost $50 billion
* November 24, 2018 - Mr Andrews steers Labor to thumping election victory, known as the "Danslide"
* May 12, 2019 - Bill Shorten pledges $10 billion to the project if Labor wins next federal election
* May 18, 2019 - federal Labor loses election, with Scott Morrison remaining prime minister
* September 3, 2019 - Victorian government announces it will create a dedicated authority to oversee the project
* June 22, 2020 - Ms Allan adds new title of minister for the Suburban Rail Loop
* November 16, 2020 - Mr Andrews announces state budget will include $2.2 billion for early works
* August 19, 2021 - a business case estimates the project's east section, also known as SRL East, will cost between $30 billion and $34.5 billion and be built by 2035 - the northern section is expected to be built by 2056
* May 10, 2022 - Anthony Albanese pledges an "initial commitment" of $2.2 billion to the project under a federal Labor government
* May 22, 2022 - Labor wins federal election
* Mid-2022 - early works begin
* August 17, 2022 - Victorian opposition leader Matthew Guy promises to shelve the project and redirect money to fix state's health system if coalition wins state election
* August 18, 2022 - Victoria's independent Parliamentary Budget Office estimates cost of building the first two stages of the project could be $125 billion
* November 26, 2022 - Victorian Labor returned to government for a third term with an increased majority
* September 27, 2023 - Ms Allan replaces Daniel Andrews as premier
* December 6, 2023 - A report by Victorian ombudsman Deborah Glass finds SRL was conceived by a single executive and handled by private consultants under a veil of secrecy
* December 12, 2023 - first tunnelling contract, worth $3.6 billion, awarded for 16km eastern section between Cheltenham and Box Hill
* March 13, 2024 - budget office analysis revises construction costs for eastern and northern sections to $96 billion
* November 10, 2024 - second tunnelling contract, worth $1.7 billion, awarded for 10km section between Glen Waverley and Box Hill
* February 3, 2025 - Federal Liberal leader Peter Dutton says the project has turned into a "cruel hoax"
* March 22, 2025 - Infrastructure Australia says it has "low confidence" in SRL East's cost estimate and argues economic benefits for the first two sections have been "overstated"
* April 1, 2025 - Mr Dutton announces he will cancel federal funding and spend it on Melbourne Airport Rail if elected
* May 3, 2025 - coalition suffers a crushing federal election defeat to Labor
* May 8, 2026 - Treasurer Jim Chalmers announces an extra $3.8 billion will be set aside for the project in the federal budget
* July 28, 2026 - Ms Allan resigns as premier following an internal revolt, with Ben Carroll appointed replacement and foreshadowing a project rethink
* August 25, 2026 - Mr Carroll announces SRL East scope changes and a technical review to find $2 billion in savings, while coalition continues to promise to pause and review project if elected in November
Australian Associated Press