This article is more than 8 months old

This article is more than 8 months old

London transport authorities do not expect the £18bn Crossrail line to open before autumn 2021, in the latest delay to Europe’s largest infrastructure project.

The capital’s transport commissioner said the latest working assumption was that the central section of the Elizabeth line, as Crossrail will be known, will start operating between September and December next year.

“We’ve looked at a delay until the later stages of 2021, in terms of our business planning assumption,” Mike Brown said. “The assumption we’ve made is, I suppose, at the pessimistic end. But it’s the pragmatic end.”

Before Brown’s announcement, Transport for London had said the line would open between 2020 and March 2021. Brown told London assembly members on Monday that Crossrail had underestimated the scale of the task remaining, with some stations apparently near completion but then requiring more work to replace systems and wiring.

TfL’s business plan, published last month, has admitted the delays would cost the organisation more than £1.3bn in lost revenue.

A further delay will be embarrassing and costly for TfL, after the London Underground boss, Mark Wild, was brought in as chief executive to improve management of the project.

The Elizabeth line was set to be opened by the Queen on 9 December 2018, a date that was postponed only three months before the official ceremony.

Brown’s guidance to the London assembly’s budget committee on Monday comes less than three weeks after Wild said he still believed spring 2021 was feasible.

Wild had initially set out the range of 2020 to March 2021 as a realistic timeframe to complete the troubled project. Challenges including rewriting signalling software would dictate when the line could open, Wild said late last year, with about nine months required for running test trains.

The target opening date is expected to be officially revised this month, after a Crossrail board meeting on Thursday.

The overall budget for the line has escalated to £18.25bn, from £14.8bn. The Elizabeth line is expected to carry more than 200 million passengers a year across London, linking Heathrow and Reading in the west and Abbey Wood and Shenfield in the east, via the West End and Canary Wharf.

A TfL spokesperson said: “The Crossrail team continues to make progress completing the railway and is moving forward with the complex testing of the signalling and train systems so that the railway can be handed over safely and reliably for passenger service. As Crossrail Ltd previously announced, the Elizabeth line will open as soon as practically possible in 2021.

“As part of our annual business planning process, we have made some prudent assumptions including that the central section of the railway could open in autumn 2021, but continue to support Crossrail Ltd in delivering the railway as soon as possible.”