Employers are putting their staff under pressure not to use the CoronaMelder app during working hours because they fear it could lead to mass absences.

Trade unions said they had received dozens of reports from people who were advised not to install the app or to switch it off so it cannot track them at work.

Companies in the retail and industrial sectors whose staff cannot work from home have the most to lose if large numbers of people are forced to spend a week or more off work at the same time.

‘Employers in those sectors don’t want their personnel to install the CoronaMelder,’ Piet Fortuyn, chair of the CNV union, told Trouw. ‘That increases the risk of coronavirus infections in the workplace.’

The rules state that anyone who receives a notification that they have been in close contact with an infected person must quarantine for 10 days and take a test if they develop symptoms.

‘It’s an issue primarily for small entrepreneurs with a maximum of nine employees who can’t work from home,’ Hans Biesheuvel, chairman of small business association Ondernemend Nederland said. ‘Think of housepainters, cleaners and lorry drivers.’

Companies are not allowed to ban employees from installing the app on their private phones, but internal memos are circulating advising them to switch off Bluetooth at work so CoronaMelder cannot track their location.

Bus company Qbuzz wrote a circular criticising the app as ‘not watertight’ and imprecise. It warned drivers that they could receive a notification if someone sitting at the back of the bus was infected with the virus.

The CNV and FNV unions have called for the government to compensate firms who lose business because staff have to go into quarantine. Wider use of fast tests could also enable people to return to work sooner.

‘If the CoronaMelder gives you a notification and you can take a test immediately and receive the result quickly, employees with a negative result can go straight back to work,’ said a spokesman for the FNV.