Downing Street said while the Prime Minister’s office was a Covid-secure workplace, it was not possible to eliminate the risk of infection altogether.

As Boris Johnson now self-isolates after coming into contact with a Covid-positive MP at Number 10, here are steps employers can take to reduce the chance of transmission in their workplace.

Risk assessments

The Health and Safety Executive (HSE) said employers should first update their risk assessments in order to see what steps should be taken to protect workers.

This includes identifying what work activity could lead to transmission, how likely it is that someone could be exposed to coronavirus, and how to remove or control that risk.

Social distancing

Staff and customers should be kept at least two metres apart, where possible, to reduce possible transmission, the HSE said.

Where this is not possible, employers should consider additional measures, such as using clear screens between people to create a physical barrier or limit the amount of equipment that people need to touch.

The HSE said people should work side-by-side, rather than face-to-face, that signage reminding people to keep apart should also be put in place.

Hygiene and cleaning

Keeping the workplace clean and ensuring people practice good hygiene is “critical” to making sure businesses are Covid-secure, HSE said.

Employers should use signage to remind staff to wash their hands regularly and properly, and to use a tissue or their arm to cover their mouths when coughing.

Hand sanitiser should be made available in areas outside of staff toilets, particularly in entrances and exits.

Meanwhile, frequently touched surfaces – such as door handles, bannisters and work stations – should be cleaned more regularly.

Face coverings

Retail, leisure and hospitality staff who work in indoor areas that are open to the public must wear face coverings, the Government has said.

This includes shops, supermarkets, pubs, restaurants, banks and public areas of hotels and hostels.

However, staff who are standing behind a physical barrier – such as a clear screen – between themselves and a customer will not be required to wear a covering.

The Government said employers should assess the use of face coverings on a “case-by-case” basis, depending on the workplace environment.