A community bus company has suspended its services after a driver died from coronavirus and another was admitted to hospital.
Andy Howe worked for CT4N, which runs a service to Nottingham hospitals. He died on 26 March.
The RMT union said it received reports drivers such as Mr Howe were not properly protected.
The bus firm said there were screens between drivers and passengers and it had followed government advice.
Following the two cases, the non-profit company said it would deep clean all facilities and "examine its processes".
Mr Howe, 48, worked on the Medilink service which took NHS workers and patients to hospital.
He died on the way to hospital after falling ill, his employer said.
A spokesman for the RMT union said: "We are saddened by the news of Andy's passing.
"We're also angered by the reports we have received about a lack of duty of care for Andy, his colleagues and the wider public."
He said this included reports of toilets and buses not being cleaned properly, a lack of protective screens and no offer of face masks.
CT4N denied the allegation and said it had been "rigorously following government health and safety advice".
A spokesman said it had introduced enhanced hand washing facilities, contactless payments and screens between drivers and passengers.
He said it was not clear how the two drivers had contracted the illness so CT4N had temporarily suspended services as a precaution.
'Devastated' by death
Andrew Grieve from CT4N said Mr Howe a "popular" and "well-respected" member of the team and said everyone was "devastated" by his death.
"From the outset we have taken this very seriously," he said.
"We think of our staff as one big family and we are concerned they get the best protection possible. We have been working up our measures as quickly as possible."
The firm said it was "in urgent discussions" with the city council and local bus providers to find a suitable vehicle to continue the Medilink service.