A “forensic focus” is required to complete Crossrail within its revised budget and timescale, an inquiry has found.

In a report seen by the PA news agency, the cross-party London Assembly Transport Committee urges Transport for London (TfL) and mayor Sadiq Khan to ensure “past mistakes are not repeated”.

It recommends they keep a “tight grasp” on the project’s leadership structures and financial stability.

Management and governance of the scheme was transferred from Crossrail Ltd to TfL – which is chaired by Mr Khan – on October 1 last year.

The Transport Committee expressed concern that there may not be “enough resources or the right level of expertise” to successfully complete its final phases, such as safety assurance activities and technical processes.

It also noted the coronavirus pandemic has “exacerbated resource constraints” and created “possible staff burnout”.

Londoners need assurance that they will be no further out of pocket and the train will be on the track by summer next year

The railway will be known as the Elizabeth Line once it opens, with services running from Reading and Heathrow in the west to Shenfield and Abbey Wood in the east, via central London.

It was initially due to be completed in December 2018 and was set a budget of £14.8 billion in 2010.

But the project has suffered from problems in a number of areas, including construction work and signalling systems.

It is due to partially open in the first half of 2022, although TfL commissioner Andy Byford has reportedly set an internal target of running services before the end of this year.

The railway was given £825 million more Government funding in the form of a loan in December 2020, taking its budget up to £18.6 billion.

Alison Moore, who chairs the Transport Committee, said: “Now that Crossrail has been handed over to the mayor and TfL to deliver, it is vital that they adopt a Sherlock-style forensic focus to make sure no aspect of delivering the project on time and on budget is missed.

“Covid-19 has understandably put increased financial and staff pressures on Crossrail opening the Elizabeth Line. However there are aspects to delivering Crossrail, such as supporting employees’ workloads and better forecasting project delays, that can contribute to delivering as promised.”

She said it is “imperative” the Elizabeth Line is “up and running as soon as possible”, adding: “Londoners need assurance that they will be no further out of pocket and the train will be on the track by summer next year.”

Mr Byford responded to the report by stating he can “assure everyone that my focus remains on safely opening the Elizabeth line as soon as possible”.

He continued: “There have been many challenges with delivering the railway and I am confident lessons are being learned and applied in these complex final stages of delivery.

“The coronavirus pandemic has obviously had some impact on the project and ways of working, and Crossrail has responded to this by ensuring sites remain a safe place to work.

“We will of course continue to ensure the London Assembly is fully updated on progress of the Elizabeth line, which is so vital for London and beyond.”