McDonald's has apologised to food delivery drivers after they were denied access to its toilets in lockdown.
It comes after the Health and Safety Executive (HSE) had to remind restaurants of their legal obligations following complaints from couriers.
Fast food chains KFC, Subway, Nando's and Wagamama have also been accused of blocking access to their facilities.
Under health and safety law, restaurants must give drivers access to "suitable sanitary conveniences".
"We apologise to any courier that has been affected," McDonald's said.
"We are sorry to hear that on some occasions this guidance has not been implemented, and we will be reminding our restaurant teams about the policy."
Takeaway delivery drivers have been crucial through the pandemic to enable restaurants to continue to trade.
But the HSE said it had received complaints suggesting some restaurants were breaching the Workplace (Health, Safety and Welfare) Regulations of 1992.
These not only oblige restaurants to provide toilet access for delivery drivers, but also washing facilities at "readily accessible places".
'Health and wellbeing'
In a joint letter to restaurant chains earlier this month, the HSE and the Department for Transport said: "Ensuring that hygiene facilities are readily available to visiting drivers is especially important during the current Covid-19 crisis, to avoid unwanted public health implications and to help tackle the spread of the virus."
This was at a time "when there are fewer locations operating with facilities that drivers can access", it added.
A spokesman for Nando's, which has also been accused to denying toilet access, said its policy was to let delivery drivers use the facilities at all of its restaurants.
"We've reiterated this to all restaurants again [this week]," he added.
A KFC spokesman said guest toilets were available for couriers at its outlets, adding: "We're ensuring all our team members are aware this is the case."
The BBC has approached Subway and Wagamama for comment.
The App Drivers & Couriers Union (ADCU) called McDonald's apology a "welcome step".
"However, the entire process for food pick up at McDonalds is a shambles which needs urgent management attention," general secretary James Farrar told the BBC.
The Unite union agreed, stressing that fast food chains and restaurants needed to heed their legal obligations to delivery drivers.
"The restaurant's staff will still be able to use the toilets and food couriers have the same legal rights to use the toilets," said Unite national officer Adrian Jones.
"McDonald's must end the ban which is endangering the health of the couriers and their customers or the Health and Safety Executive should take immediate action."
Full BBC article can be found here https://www.bbc.co.uk/news/business-54994472