British Prime Minister Boris Johnson on Tuesday said the UK's high-speed railway HS2 will be built despite soaring costs, bringing faster and greener transport connections between London and northern England.
Addressing parliament, Johnson said his "cabinet has given high-speed rail the green signal".
He added: "We are going to get this done and to ensure that we do so without further blowouts to costs or schedule; we are today taking decisive action to restore discipline to the programme."
Johnson's full backing comes after he ordered a review into the viability of the line, the largest current infrastructure project in Europe, after years of delays and ballooning costs.
Some projections suggest HS2 could cost more than €118 billion, double an official 2015 estimate, and far more than was suggested when HS2 was first mooted in 2009.
HS2 will be Britain's second high-speed rail project after HS1, the line linking London with the Channel Tunnel to France.