MPs have been told to wear face masks and tours of Parliament are being cancelled, following rising COVID cases on the parliamentary estate.
Committee chairs will also be asked to take a stronger role in ensuring MPs comply with coronavirus rules.
A parliamentary spokesperson said that “recent increases in COVID across the country… are also being reflected in Parliament”.
The measures will be reviewed later this month.
Face coverings became mandatory for staff employed by the House of Commons, unless they have a legitimate exemption, at the end of October but it was left up to individual MPs to decide whether to cover their faces or not.
MPs are not employed by the Commons authorities and cannot be forced to wear masks - although they have been encouraged to do so by the Commons Speaker Sir Lindsay Hoyle and unions representing parliamentary workers.
Most opposition MPs have opted to wear masks during Commons debates, but many Conservatives have not. And last month, minister Jacob Rees-Mogg said Conservatives did not need to wear masks because they knew each other well, and this meant they were complying with government guidance.
The latest advice says people in England should cover their faces around “people you don't normally meet”.
In a statement, a parliamentary spokesperson said their priority was “to ensure that those on the estate are safe”.
“The UK Health Security Agency (UKHSA) has determined that the risk of transmission on the Parliamentary Estate is now greater.
“As a consequence, some further action is being taken to ensure that case numbers do not continue to rise.”
The new measures include cancellation of non-parliamentary business activity such as tours and banqueting activity - in addition to asking MPs and peers to wear face coverings.
People in Parliament will also be asked to maintain social distancing - particularly in committees where the risk of transmission is believed to be greater.
Labour MP Ben Bradshaw tweeted: “You get chucked out of Parliament for not wearing a jacket and tie. If you won't wear a mask, a recommended public health measure to protect others, nothing. What an antediluvian Alice in Wonderland this remains.”
BBC News November 2021