For the latest legal developments, see this digestible summary which has just been published by the Government https://www.gov.uk/guidance/government-support-available-for-landlords-and-renters-reflecting-the-current-coronavirus-covid-19-outbreak?utm_medium=email&utm_source=
Pending possession action is halted. Any landlord now wishing to give notice to a tenant to leave will be required to give at least three months' notice (instead of 28 days, 14 days or two months, depending on the type of tenancy, as before). New forms of notice are likely to be prescribed shortly.
But - and it's a big but - rent will still be payable. If two months' plus rent arrears accumulate then (subject to any future legislation) a large number of tenants will be at risk in due course - once the freeze on possession proceedings thaws out - of being subject to a mandatory order for possession. So try and keep those arrears down to less than two months.