National Audit Office poised to launch inquiry into rail route upgrade, which has doubled in cost

PA Images Network Rail

The National Audit Office is set to launch an investigation into the soaring cost of Network Rail’s electrification of the Great Western mainline, according to the Sunday Times.

The watchdog is gathering evidence on the project and is likely to launch an inquiry, according to the report.

Electrification of the Great Western route from London Paddington to Swansea has jumped in cost from £1.6bn to £2.8bn.

Problems such as striking buried cables and raising bridges mean it still has no firm date on when the work will be complete, the report adds.