Ministers are "actively considering" axing the entire HS2 scheme, a documentary is set to reveal tonight. 

Channel 4 Dispatches will investigate whether High Speed Two (HS2) - a high-speed rail line connecting London to Birmingham by 2026 and then Manchester and Leeds by 2033 - will bring the jobs and economic growth the government is promising.

In 2011 the estimated cost of the project - which has been branded a "white elephant" by campaigners against the controversial project - was £33 billion.

Four years later the official forecast had ballooned to £56 billion - but some experts are predicting a £100 billion final bill.

Dispatches correspondent Liam Halligan says a senior cabinet source hs revealed ministers are considering saving costs by only building HS2 to Birmingham and are "actively considering" axing the entire HS2 scheme.

It comes as an exclusive poll for Channel 4 Dispatches, conducted by ComRes, revealed that only 20 per cent of voters want the multi-billion-pound High Speed line to be built.

Just seven per cent - less than one in 10 - think HS2 will benefit them to any extent. 

Mark Thurston, the new HS2 Chief Executive, insisted to Dispatches he will keep the scheme on budget. 

He said: “What I'm very clear on and what HS2 is very clear on is that the budget for this scheme is £56 billion.

"That’s the task we've been set by government and that's what we work on until government advise us otherwise."