High speed train of the type proposed for the HS2 network
The winning bidders of £6.6bn of contracts to build the first phase of Britain’s HS2 between London and Birmingham have been announcedReuters

The winning bidders of £6.6bn ($8.6bn) of contracts to build the first phase of Britain's HS2 between London and Birmingham have been announced, amid fresh controversy over rising costs at the high speed rail project.

UK companies Carillion, Costain and Balfour Beatty are among the consortia who will build tunnels, bridges and embankments on the first stretch of the new high speed rail line.

Around 16,000 jobs will be supported by these first-stage contracts, which is due to see trains running by 2026.

HS2 trains are expected to carry up to 300,000 passengers a day, freeing up thousands of seats on local services. It could help double the number of seats on rush-hour services leaving Manchester and Leeds and potentially double the number of seats available from London to Peterborough.

The government also confirmed plans to extend HS2 from Birmingham to the North West, East Midlands and Yorkshire.

But the contract award comes as an independent expert calculated that the initial section will cost almost £48bn, making it the most expensive railway in the world and 15 times the cost per mile of the latest TGV line in France.

In documents first obtained by the Sunday Times at the weekend, Michael Byng, who worked alongside Network Rail to devise its method for costing projects, estimated costs for the first stage of HS2 which, if extrapolated, would result in a £104bn price tag for the full project.

But Transport Secretary Chris Grayling said the higher figure is "just nonsense". He added the project would be "on time, on budget" at £55.7bn.

The inclusion of Carillion, the troubled construction company, among the first tranche of contract winners will also raise eyebrows.

Rebalance the economy

The company, which last week lost three-quarters of its share price following a profit warning, was awarded two contracts to build the the North Portal Chiltern tunnels to Brackle, along with Eiffage Genie Civil, Kier Infrastructure and Overseas Ltd.

Grayling said: "This is a hugely important step in the construction of Britain's new railway and underlines this government's determination to deliver an economy that works for all.

"HS2 will deliver vital links between some of our country's biggest cities, helping to drive economic growth and productivity in the north and midlands.

"As well as providing desperately needed new seats and better connecting our major cities, HS2 will help rebalance our economy."

The Department for Transport said preparatory work has begun and major construction work is due to start in 2018-19.

TUC Deputy General Secretary Paul Nowak added: "This is a shot in the arm for Brexit Britain. It will provide thousands of decent jobs, billions in investment, and help close the north-south divide."

However, critics of the scheme condemn its financial and environmental cost.

Joe Rukin, of the Stop HS2 campaign, said: "The case for HS2 has been invented by the very cheerleaders who intend to rake in billions of taxpayers' money which is desperately needed elsewhere, so it really is time to ditch this gigantic white elephant before it is too late."