Construction of HS2 has officially started today (4 September) with what the government is calling a "shovels in the ground" moment.
Boris Johnson says the high-speed railway will create thousands of jobs and introduce vital links between cities throughout the country.
He said: "HS2 is at the heart of our plans to build back better - and with construction now formally under way, it's set to create around 22,000 new jobs."
"As the spine of our country's transport network, the project will be vital in boosting connectivity between our towns and cities."
Speaking at the construction site at the Solihull interchange Mr Johnson said that the project is "crucial for our country" and passengers will be able to reach London in just 38 minutes.
What happens now?
The four main contractors for Phase One between London and the West Midlands will now switch from enabling works, scheme design and preparatory work to full construction.
Construction will begin with the biggest engineering challenges – such as the stations and tunnels – followed by the main viaducts and bridges.
Most activity this year will be focused on HS2’s city centre stations such as Curzon Street in Birmingham.
How much will it cost?
A review last year warned that the final bill for the HS2 could reach £106billion.
Despite the project running billions of pounds over the initial budget- and already being several years behind schedule- the PM gave it the green light in February 2019, along with a revised budget.
What is the route?
The first phase of the project between London Euston and Birmingham is set to be completed between 2029 and 2033.
Trains will then run further north on the existing West Coast Main Line.
Phase 2 of the project is set to run from Birmingham to Leeds and from Birmingham to Manchester. This phase was due to open between 2032 and 2033 but has now been delayed to as last as 2040.
What will the new journey times be when it's complete?
Trains are expected to travel at speeds up to 250mph.
When the first phase of the project is complete The Department for Transport says journey times from Birmingham to London will be be cut from 1 hour 21 minutes to 49 minutes.
When the second phase is complete journeys from Birmingham to Leeds could be reduced to 49 minutes rather than 2 hours.
Why is it causing controversy?
Campaigners say that the construction work will devastate many natural habitats and bring disruption to villages.
The Woodland Trust states that 108 ancient woodlands will be damaged due to HS2, 33 sites of Special Scientific Interest will be affected and 21 designated nature reserves will be destroyed.