THE UK government has played down reports that Chinese companies could get involved in the construction of the high speed rail network HS2.

Trade magazine Building reported that China Railway Construction Corporation (CRCC) recently wrote to HS2 Ltd's chief executive, saying it could build the line in around five years, for a much-reduced price tag.

The CRCC letter, which has also been seen by the Financial Times, said that “we are certain that we can offer a cost that is significantly lower than the projections we have seen”.

Last week Prime Minister Boris Johnson finally gave the green light for HS2, in spite of concerns that costs might spiral from the budgeted 62 billion pounds sterling to over 100 billion pounds sterling.

Appearing on BBC TV, Transport Secretary Grant Shapps said that there were currently no talks between the UK government and Chinese companies over the project.

"This has not been a discussion with the Department [of Transport], it's been a discussion with HS2 as I understand it,” says Shapps, adding that “obviously I will be asking to see what the communication has been”.

HS2 is the UK’s single biggest and most expensive infrastructure project. The city centres of London, Birmingham, Manchester, and Leeds will be connected by 345 miles of new high-speed railway track. HS2 is expected to carry over 300,000 passengers a day when fully operational.

Under current plans, the final stretch of the line is not due to be completed until 2040 - though Johnson has said that he would like that date to be brought forward to 2035.