London Assembly members have called for the commissioner of Transport for London (TfL) to resign following delays to the opening of Crossrail.

The Elizabeth Line – whose implementation is managed by the company Crossrail Ltd – is set to run from Reading and Heathrow into central London and then through to Shenfield and Abbey Wood in the east.

The project is joint funded by TfL and the Department for Transport.

The line was supposed to have opened in December 2018 but in August the same year it was announced it would not be opening until autumn 2019.

Earlier this year Crossrail Ltd admitted it could not commit to an opening date.

Now a report by the London Assembly transport committee – which looks into the delayed opening of the Elizabeth Line – suggests TfL’s commissioner, Mike Brown, should step down.

The report says: “TfL’s commissioner must reflect on whether he is fit to continue to fulfil his role at TfL.”

Committee chairman Caroline Pidgeon said: “It is shameful that nobody at a senior level is willing to take responsibility for the failure of the project thus far.

“Crossrail’s former chairman, Sir Terry Morgan stepped down, however, the evidence suggests that TfL Commissioner Mike Brown was at the centre of decisions to dilute important information sent to the Mayor.”

The report said that emails between Crossrail and TfL suggest that communications to Mayor of London Sadiq Khan about the state of the project were “watered down” by Mr Brown, instead of flagging the risks to him.

The report also says in the future the project needs to be more transparent and has called for Crossrail board meetings to be made public and recorded.

It also said concerns raised by the independent reviewer of the project were largely ignored and the “desire to achieve” the completion date was overpowered any professional and critical assessment of risk.

Ms Pidgeon added: “Crossrail was supposed to be the beacon of modern 21st century engineering but its name is now tarnished with shame in the eyes of the London taxpayer who will have to foot the bill until its completion.

“The inability of senior figures in the project to push past their obsession with a December 2018 launch date is one of the main reasons why their dream did not become a reality.”

A spokesperson for TfL said the delay for to the Crossrail project lies with the former management at Crossrail Ltd, not TfL or Mr Khan. Former Crossrail chairman Terry Morgan stepped down last year.

The spokesperson added: “The Commissioner works to ensure that the Mayor is kept informed of everything going on in transport in London and to ensure the information he receives is clear, consistent and accurate.”