Network Rail’s current five-year investment programme is fatally flawed by 'severe planning and budgeting failures', according to an influential group of cross-party MPs.
The Commons' Public Accounts Committee's latest report prompted chair, Meg Hillier, to call for a 'fundamental review' of the Office of Rail and Road's (ORR) role in infrastructure planning of industry regulator.
The report has singled out for particularly heavy criticism the 'staggering and unacceptable' cost increases in the project to electrify the Great Western Main Line from London to Cardiff, now expected to cost up to £1.2bn more than the 2014 estimate of £1.6bn.
It found that there was still 'far too much uncertainty' over the costs and likely delivery dates of two more electrification schemes, for the TransPennine route and the Midland Main Line.
Further projects, it warned, could also now face delays arising from the need to balance Network Rail’s budget.
The Department for Transport and Network Rail need to have 'a clear and agreed public strategy' about which rail projects are deliverable, with deadlines for key milestones that are 'clear, realistic, and transparent to passengers and the public', the MPs said.
Ms Hillier added: 'Network Rail has lost its grip on managing large infrastructure projects. The result is a twofold blow to taxpayers: delays in the delivery of promised improvements, and a vastly bigger bill for delivering them'.
The recently reclassified public body has also failed to deliver target savings on renewal work.
The committee went on to slam current five-year funding cycles, while appropriate for ongoing operations, as being unsuitable for major investment projects.
The review of the ORR will investigate its signing off, together with the Department for Transport and Network Rail, of an 'unrealistic' programme of rail investments for 2014-2019 which 'could never have been delivered within the agreed budget and timeframe'.
Network Rail chair, Sir Peter Hendy, who joined in July 2015 from his role as Transport Commissioner for London, has been charged with producing a detailed report on how a revised and re-costed electrification programme can now be made feasible.