A “catastrophic” backlog in processing driving licences is due to management decisions which “put people at risk”, MPs have heard.

Mark Serwotka, general secretary of the Public and Commercial Services Union (PCS), which represents the workers at the Driver and Vehicle Licensing Agency’s (DVLA) offices in Swansea, South Wales, said an agreement on improved working conditions was withdrawn “without any explanation”.

There have been 643 coronavirus cases at the site including one person who died, he told the Transport Select Committee.

It has taken management decisions that we believe put people at risk

Mr Serwotka said: “The DVLA has had the single biggest Covid outbreak of any workplace in the UK.

“It’s operated out of central Cabinet Office guidelines for handling the Covid pandemic.

“It has taken management decisions that we believe put people at risk.”

He explained that the number of people being required to work in an office rather than from home is “what has caused the huge amount of Covid cases”.

No other Government offices have had similar outbreaks of the virus, Mr Serwotka said.

He continued: “None of them require the same amount of people to be in work as the DVLA and all of them have been able to deliver their business, including DWP (Department for Work and Pensions) and HMRC (HM Revenue and Customs), with staff working from home.

“The reality is, in DVLA we were told ‘the management didn’t trust’ lower-ranked workers to work from home ‘because they couldn’t supervise them’.”

There have been concerns from motorists, trainee drivers and lorry drivers about long delays in receiving documents from the DVLA.

PCS members have launched a series of strikes as part of a campaign for more safety measures to be taken, including a reduction in the number of staff expected to work at the site.

Further action is planned.

Mr Serwotka said: “The catastrophic state of the backlog at the DVLA in Swansea is primarily now down to the industrial dispute that exists between the workforce and the DVLA management.”

DVLA chief executive Julie Lennard told the committee that the disruption is affecting paper rather than online applications.

The typical waiting time for paper applications to be processed is “six to 10 weeks” but more complex cases such as those involving medical declarations can take longer.

On the issue of some staff not being permitted to work from home, Ms Lennard said “I don’t accept that there’s a cultural issue”.

She noted that 2,000 people are being allowed to work from home, but insisted some roles must be office-based as they deal with “huge amounts of personal data”.

She added that less than a third of the backlog is caused by the industrial action, with most of the disruption due to reduced staffing levels caused by social distancing.

Roads minister Baroness Vere said the Department for Transport “will continue to try and reduce it where we can” through measures such as considering whether someone who is not a GP but is “equally qualified” can make decisions on medical cases.

She insisted that no deal was agreed between the agency and the union because “the goalposts moved around”.

She told the MPs that despite the strike being balloted “on the basis of Covid safety”, the proposals from the union included bonuses and extra holidays.

“I struggled to reconcile that with the reason for the industrial action in the first place,” Baroness Vere said.

Speaking after the hearing, a DVLA spokeswoman said: “The safety of our staff is paramount and since the beginning of the year we have implemented weekly Covid testing for everyone.

“Since the outbreak of the pandemic we have reorganised our eight buildings in line with official advice, and utilised space in a newly-leased building to further assist with social distancing measures.

“We have also installed thermal imaging cameras to carry out temperature checks on people entering the buildings.”