The new boss of the planned high speed rail link linking London and Birmingham has been tasked with finding ways to cut the estimated £50 billion cost of the scheme.            

Prime Minister David Cameron told the CBI annual conference in Manchester this morning that the first task of the project’s new boss, Sir David Higgins, will be to report on lowering costs and maximising benefits.            

He said: “Our infrastructure is decades out of date and we urgently need to invest and build.            

“Those who want to delay or obstruct HS2 show a lack of vision. They are playing politics with Britain’s prosperity. They are betraying everyone north of Watford. I ask everyone across politics to put their own interests aside - and put the national interest first.            

”Sir David, who takes over as HS2 chairman next year, has indicated he believes the scheme can come in at “substantially” less than current estimates by trimming the £14 billion earmarked for contingency costs.            

Mr Cameron said: “He has agreed that the first vital step will be to bring his penetrating eye and expertise to a specific task. To report on the costs. And to maximise the benefits for all parts of the country as quickly as possible. He has already said the line could come in “substantially” under the current budget. And he has also made it clear he needs cross-party support to do it.”            

The PM said he was “passionate” about the HS2 scheme.  “We need to build new railway lines in our country. We haven’t built a line north of London for 120 years.            

“The West Coast Main Line is full. Thousands of our fellow-countrymen are standing every day as they come into Euston or go into Birmingham. We need to build another West Coast Main Line.”