Cost of modernising large section of London Underground rises by more than £1bn

The price tag for modernising a large section of the London Underground has risen by more than £1bn.

Credit: PA

The upgrade of the 'sub-surface' lines will also be more than three years later than planned.

The rising cost and delays have been caused in part by the collapse of a crucial contract to replace 'antiquated' signals.

Credit: PA

London Underground abandoned a deal with Bombardier in 2013 with an estimated loss of almost £100m.

The modernisation of the Circle, District, Hammersmith & City and Metropolitan Lines will now be completed in 2022 instead of 2018.

The total bill has risen by 30% from £4.26bn to £5.54bn.

London Underground said the commuters would see a significant improvement in services.

The number of trains on the Circle Line is to double with a frequency of one every four minutes instead of every ten minutes.

The overhaul of the next set of four lines and installing new signalling is a hugely important task and one that we must get right.

By upgrading 40 per cent of the Tube network we will create space for tens of thousands of extra passengers each hour.

This will help to ensure London's position as the greatest global city, its continued economic success and cement its reputation as a fantastic place to live, work and visit.

– Boris Johnson, Mayor of London

Labour said the collapse of the Bombardier signalling contract had caused 'expensive chaos'.

The idea that the Mayor thinks today’s announcement is something to boast about is stunning.

Not only are these upgrades now expected to complete four years later than planned, the new contract comes after the Mayor and TfL wasted over £85m of taxpayer money on the disastrous failure of the previous Bombardier deal.

These lines are already operating ridiculously close to capacity and now we learn that as a result of the Bombardier fiasco, commuters will have to wait an extra four years to see the improvements they were promised.

– Val Shawcross, Labour member London Assembly