London’s Deputy Mayor for Transport has today rejected calls for independent scrutiny of Transport for London’s (TfL) conduct in the wake of the Croydon tram crash.

Heidi Alexander said she was “confident that a further independent investigation is not required” after TfL failed to share a tram driver fatigue audit with crash investigators.

Seven people died in the Croydon crash and a further 62 were injured, after a tram derailed near Sandilands junction in 2016.

Following the crash, amid concerns around tram driver exhaustion – including video footage of drivers asleep at the wheel – TfL carried out its own report into driver fatigue.

But the transport network failed to share this document with investigators after being instructed to by its own board members.

Once the “human error” was uncovered, TfL rectified the situation by sharing the report.

But last week, Buzzfeed News revealed recommendations in the draft report were softened in the final version.

The conclusion that tram operation “requires improvement” was removed from the report and “priorities” were downgraded to “opportunities for improvement”.

But speaking at the London Assembly’s transport committee today, Ms Alexander said the changes were part of “normal practice” in auditing.

She said: “Substantively the recommendations and the findings of that audit have not been changed. There’s been some minor revisions, some reordering.”

She added: “The important thing here is what steps have been taken to make sure that the tram network is as safe as possible and that never again will a tragedy like Sandilands occur.”

But the Mayor’s Office faces mounting pressure to fully investigate the alleged “human error” which resulted in the TfL audit not being shared.

Former TfL board member Michael Liebreich – who chaired the transport network’s safety panel at the time of the crash – wrote to the Mayor earlier this week to request an enquiry.

Mr Leibreich told the transport committee today that he had “more questions rather than fewer” as time went on and found this “quite disturbing”.

He said: “I can’t begin to know what it feels like to be the family of one of the victims that lost their lives, but that’s what’s driving me to say I’m not happy and I think we need answers – that the families need to know the answers.”

Conservative assembly member Keith Prince, who has repeatedly called for an investigation, said scrutiny was more necessary than ever.

He said: “When I initially had questions about the report not being sent on time to the Rail Accident Investigation Branch I thought this was probably more cock up than conspiracy, because invariably these things are.

“But there are two things in back of my mind now. One is that that there’s a very strong push back from Mayor’s Office to any investigation, which is very strange.

“The second is that there’s more and more stuff coming out: the draft report was changed, the board was given assurances that there was nothing to see here.

“The more we get this stonewalling from the Mayor, the more it seems there is to hide.”

Mr Prince added that “you could bet your bottom dollar” that a Conservative mayor – Shaun Bailey, the candidate for 2020 – would launch a full enquiry.

Liberal Democrat assembly member Caroline Pidgeon, who has also called for an investigation, agreed that independent enquiry remained “absolutely necessary”.

She said: “We still have a lot of questions for TfL to answer on its past record on safety issues and especially why it failed to share vital information while the investigations into the Sandilands tram crash were being undertaken.

“If we are to deliver safer travel in the future we need to fully understand why mistakes were made in the past.”

Tom Kearney, a businessman and bus crash survivor who campaigns on transport safety, said the Deputy Mayor had failed to present any new evidence.

He said: “It seems so strange that City Hall is willing to die on this hill.

“If they’re so confident that it’s just a cock up then an independent investigation would settle it in no time.

“But to come to City Hall with wagons circled and offer no new evidence suggests the Mayor is choosing to go to ground instead of being transparent.”