Rail electrification projects in the south of England are running up to four years behind schedule, Network Rail has admitted.
The electrification of the Great Western line between London and South Wales, already heavily over its original £874m budget, was due to be completed by 2018. However, some routes that were expected to be finished even earlier may not be ready until 2020. That includes electrification at Bristol Temple Meads station, initially scheduled for completion in December, Oxford electrification, delayed from 2016 to 2019 and Newbury, postponed from 2015 to 2018.
"The Great Western main line to Cardiff - which forms the backbone of the electrification project and will carry the vast majority of services and passengers - will be electrified by 2018, the year originally envisaged,” Network Rail spokeswoman told the Press Association.
"The scale and complexity of the electrification project, together with the other extensive upgrades we are carrying out, mean we will electrify other lines later than originally planned.”
He added the firm is investing massively into the project.
Network Rail admitted in October that the cost of the project could reach £2.8bn despite a January 2013 estimate of just £874 million.
"We will do everything we can to help Network Rail meet and where possible exceed their programme in the best possible way for customers,” Great Western Railway, which operates trains on the route, said in a statement.
"However, for now we will be working with Network Rail and the Department for Transport to investigate alternative ways of delivering the full package of capacity and frequency improvements we promised in the new GWR franchise, despite the challenges of late electrification."