UK health and safety rules are expected to toughen the requirements on social distancing and ventilation at work, making COVID-secure workplaces even harder to achieve.

The new rules could be significant when the current English lockdown ends. The government has indicated a minimum seven-week lockdown to mid-February, but the lockdown regulations expire on 31 March.

The new B.1.1.7 variant of the coronavirus is now believed to be up to 70% more transmissible.

Public Health England and the Health and Safety Executive will replace guidance originally issued in March 2020, when knowledge about the virus was strictly limited and before the new variant was discovered.

Under pressure from trade unions and others, the new guidelines are expected to lead to tighter controls to prevent aerosol transmission, the Financial Times reported.

Trade unions have argued that guidance should reduce the number of people permitted in a space at any time and mandate the required wearing of face coverings in all indoor workplaces, as well as impose improved ventilation standards.

The latest guidance for offices and contact centres is badged as having been updated on 21 December 2020, three days after the new variant was announced. But the change related only to the introduction of Tier 4 restrictions, and it did not extend beyond advising the need to consider high-risk individuals and enforce shielding for those with particularly severe risk.

The revised guidance is likely to reduce headcounts in COVID-secure offices but will also affect many other workplaces including industrial sites, logistics and construction where transmission was thought to be more limited.

The Department of Business, Enterprise and Industrial Strategy said the guidance was under constant review.