The obligation to use masks for the covid19 to reduce the risk of contamination.

The reason for the use of the mask is to reduce the risk of infection by the covid-19 virus in close distances from person to person, especially in places with crowds, public transport, hospital and workplaces.

You may wish to sign this petition calling for the same action.

Make it mandatory to wear a face mask in public during Covid-19 Pandemic: Make it mandatory to wear a face mask in public during Covid-19 Pandemic

You can find out more about coronavirus and how you can protect yourself and others here:

NHS website: https://www.nhs.uk/conditions/coronavirus-covid-19/
UK Government website: https://www.gov.uk/coronavirus

You can read NHS tips to help if you are worried about coronavirus here: https://www.nhs.uk/oneyou/every-mind-matters/coronavirus-covid-19-anxiety-tips

You may also be interested to know that because of the large number of petitions that have been started in relation to coronavirus, the Petitions Committee has been questioning the Government about its response to the coronavirus outbreak.
 
Find out more and watch the Committee put questions suggested by petitioners to Government Ministers and the Deputy Chief Medical Officer: https://committees.parliament.uk/committee/326/petitions-committee/news/145767/committee-question-deputy-chief-medical-officer-and-ministers-on-coronavirus-response/
 
Read correspondence with Government Ministers asking further questions: https://committees.parliament.uk/committee/326/petitions-committee/publications/3/correspondence/