INTERNATIONAL NEWS - British Prime Minister Boris Johnson is expected Tuesday to announce his support for the HS2 high-speed railway, despite concerns about soaring costs and opposition from his own MPs.
Johnson had ordered a review of the viability of the line, the largest current infrastructure project in Europe, after years of delays and ballooning costs.
But he is set to announce to the House of Commons his support for the project, which aims to connect London to central and northern England.
Preparations for the first stage of the line to Birmingham are already well advanced, but the BBC said he would also back the second phase to Manchester and Leeds, while seeking changes to rein in the cost.
Some projections suggest HS2 could cost more than £100 billion ($129 billion, 118 billion euros), double an official 2015 estimate, and far more than was suggested when HS2 was first mooted in 2009.
HS2 claims that its trains will connect around 30 million people when it is complete - almost half the UK population - delivering faster journeys and taking pressure off existing rail networks.
It also says that the project will tackle climate change, by taking cars off the roads.
Many MPs, including in Johnson's Conservative party, have said the money could be better spent on other transport services.
There are also concerns about the impact of building the line on wildlife and the environment, as the line goes through numerous sections of ancient woodland.
However, the prime minister is known for his enthusiasm for infrastructure projects, and promised in the December election to rebalance Britain's London-centric economy by investing in northern England.
Ahead of the HS2 announcement, he unveiled funding to improve bus networks for every region outside London, including a new fleet of zero-emissions vehicles.
The main opposition Labour party said the scheme should go ahead, but transport spokesman Andy McDonald said the government must "get a grip with the spiralling costs".
The British Chambers of Commerce also welcomed the news, but said it was important that the whole line be built to ensure benefits across the north of England.
"It's time to stop debating and start delivering the new capacity and connections that HS2 will bring to our communities and businesses," said director general Adam Marshall.
But the right-wing Institute of Economic Affairs said it was "deeply disappointing".
"The costs are now likely to exceed the benefits," said the think tank's head of transport, Richard Wellings.
The previous government last year noted that HS2 costs had soared owing to the complexity of building in densely populated cities and challenging ground conditions.
The line runs through some high-end real-estate, as well as through ancient woodlands and archaeological sites, including a burial ground for 40,000 bodies underneath London's Euston Station.
At the same time, it was revealed that rather than opening in 2026, the first phase of HS2 would not operate until sometime between 2028 and 2031.
Preparatory costs are said to have already hit eight billion pounds.
HS2 would be Britain's second high-speed rail project after HS1, the line linking London with the Channel Tunnel that goes on to connect the UK with France.
Governments around the world are under pressure to promote cleaner travel as they try to limit climate change by cutting carbon emissions.
As part of a wider plan to promote greener transport, the German government last month agreed to pump 62 billion euros ($68 billion, £53 billion) into its rail network.