Delivery workers have been operating alone since the beginning of the lockdown period to prevent the spread of Covid-19.
But this week Royal Mail asked workers to begin sharing delivery vans again.
Choosing to work in the same van as a colleague is on a voluntary basis, said Royal Mail, but the Communication Workers Union slammed the “reckless” decision and warned that some workers may feel obliged to share a van despite not feeling safe doing so.
It comes after ten postal workers tested positive for Covid-19 in an outbreak at the Bathgate delivery office.
One person had previously tested positive at the Dunfermline delivery office in September.
Deputy Secretary General (Postal) of CWU Terry Pullinger criticised the timing of the decision, and accused Royal Mail of implementing it because of the run-up to Christmas rather than being guided by the severity of the pandemic.
“In the last couple of weeks, the landscape has drastically changed,” he said.
“It’s getting worse, with areas of this country getting shut down. To now make the move to put two people back in the van is reckless.”
A CWU spokesperson warned that workers may feel intimidated into sharing vans.
“Any instance of workplace intimidation over taking up entirely voluntary positions is absolutely unacceptable,” they said.
“If any Royal Mail workers feel that they are being intimidated, bullied or pressured into van sharing roles, they should speak to their CWU workplace representative immediately.”
One postal worker based in Edinburgh who did not want to be named said: “The biggest worry is that the big bosses at Royal Mail have come out with a beauty – they now want us to van share again.
"We have been working solo since April and now when the virus is on the up this is what they come out with, they say it’s voluntary. We’ve been advised by our union not to share vans. Most of us think that Royal Mail are panicking about Christmas."
Royal Mail said the company puts the health of staff and customers first, and insisted that van sharing is voluntary only.
A spokesperson said: “Throughout this pandemic, every decision we make puts the health of our colleagues and customers first. We have carefully followed Government health guidelines throughout.
"We have been in regular discussion with CWU about the voluntary reintroduction of shared vans and ensuring we have the appropriate risk assessments in place.
"Following careful consideration of all the evolving guidance and the relevant safety and wellbeing aspects, we have taken the decision to allow shared vans to be re-introduced on a voluntary basis with preventative measures in place and having followed rigorous and thorough risk assessments.
"Face coverings will be mandatory, and employees who are in the extremely clinically vulnerable category are exempt from sharing vans”.