HS2 has been the topic of much debate since plans emerged more than a decade ago.
With at least another decade to go until the project is completed, the journey to HS2's final stop will likely include plenty more debate.
After Boris Johnson gave the green light to the project, here's how HS2's eventful led to today's breakthrough.
- January 2009: Labour establishes HS2 Ltd to examine the case for a new high-speed rail line.
- December 2010: A consultation on a route for HS2 from London to Birmingham, with a Y-shaped section to Manchester and Leeds, is published by the Conservative-Liberal Democrat coalition.
- January 2012: Transport secretary Justine Greening announces the Government has decided to go ahead with the project, despite concerns over its cost and the environmental impact of construction.
- November 2013: The High Speed Rail (London-West Midlands) Bill setting out the powers needed to build Phase 1 of HS2 between London and Birmingham is introduced to Parliament.
- January 2014: The Supreme Court rejects outstanding appeals by opponents of the rail scheme.
- June 2016: The National Audit Office warns HS2 is under financial strain and could be delayed by a year.
- September 2016: Simon Kirby resigns as HS2 Ltd chief executive.
- February 2017: The High Speed Rail (London-West Midlands) Bill achieves Royal Assent, enabling preparation work to begin.
- July 2017: HS2 Ltd accepts it was a "serious error" to make £1.76 million of unauthorised redundancy payments to staff.
- December 2018: Sir Terry Morgan resigns as chairman of HS2 Ltd amid criticism over his role as chairman of Crossrail, which is delayed and over budget.
- August 2019: The Conservatives commission a review into whether and how HS2 should continue. It will be led by former HS2 Ltd chairman Douglas Oakervee, with long-term critic of the project Lord Berkeley acting as his deputy.
- September 2019: A report by HS2 Ltd chairman Allan Cook says the railway may not be completed until 2040, and the scheme could cost £88 billion.
- January 2020: The Oakervee Review is widely leaked. It finds that HS2 could cost up to £106 billion, but concludes "on balance" that the project should continue.
- December 2026: High-speed trains between London and Birmingham were due to begin running by this date, but HS2 Ltd admits this is "not viable".
- 2027: Phase 2a from Birmingham to Crewe was due to open this year, but that is also subject to delay.
- 2033: HS2 was due to be completed by this point, with Phase 2b running from Crewe to Manchester, and Birmingham to Leeds.