Corona restrictions

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Good morning.
I have a five room HMO that is fully let. During the last few months I have stopped my tenants from having visitors to prevent the virus from coming into the house. They have been happy to follow this rule.
Firstly, can I legally do this?
If one tenant contracts the virus the whole house will be effected and this will require 14 day self isolation and possibly impact on their work, I may also catch the virus.

I have a new tenant that has flouted the rules (her tenancy started 7 days ago!) despite being told the current rules. If she continues to break the Covid 19 restriction, I shall have no option but to evict her from the house ASAP. In these circumstances, would evicting her with 24hrs notice cause problems as this is not a regular situation? She was issued a 3 month AST but has only been in the house one week.

Thanks in advance.