The government’s spending watchdog is to launch an inquiry into the delays and spiralling costs on Network Rail’s Great Western Main Line electrification project.
The National Audit Office confirmed that it was “likely to launch an investigation” looking into the problems that have beset works on the line.
It said that while the exact scope of the inquiry was not yet known, details could be finalised as early as March.
The NAO has already begun gathering preliminary evidence in anticipation of an inquiry.
The £874m electrification of the Great Western Main Line was announced in 2012 as one of the major projects to be carried out as part of Network Rail’s Control Period 5 enhancement programme.
The work was expected to electrify the line from Paddington to Swansea by 2018. However, since 2014 it has suffered a number of setbacks with costs escalating to £2.8bn, and is now not expected to be completed until well into CP6, which starts in 2020.
In October, Network Rail chief executive Mark Carne revealed the extent of the line’s escalating costs in a statement to the public accounts committee, which was looking into the operator’s handling of the £38.5bn CP5 investment programme.
At the subsequent PAC evidence session, MPs called Network Rail’s overspends “staggering” and vowed to further investigate the reasons behind the dramatic cost increase.
Last month, an updated version of Sir Peter Hendy’s review into Network Rail enhancements was released, revealing that completion of the electrification would be up to four years late.
The news of a fresh probe into Network Rail comes just weeks before former High Speed 1 boss Nicola Shaw publishes her much anticipated report into the structure of the government-owned operator.
There is increasing speculation that the report could see Ms Shaw suggest a major overhaul of the UK’s rail system, including the break-up and privatisation of Network Rail.
Last week, free market think tank the Institute of Economic Affairs released a report that said a full privatisation of the UK’s railways would improve services and ease the burden on taxpayers.
A Department for Transport spokeswoman said: “Sir Peter Hendy’s rail upgrade re-plan will deliver the biggest programme of rail modernisation since Victorian times, and we areabsolutely clear that we will see the job through to deliver better journeys for passengers.
“Although this means that some programmes will take longer thanoriginally planned, we are working with the operators and Network Rail to ensure that passengers benefit from this investment and the planned cascade of rolling stock as soon as possible.”