Before the coronavirus outbreak, if a tenant lost their job they could get their rent paid through the HAP scheme. This is still the case now so I don't think it's fair that the landlord should be hit in the pocket too.
The government should make it faster for HAP applications to be processed, that way the tenant isn't liable for the rent and the landlord will still be able to pay his mortgage. It's no good the banks giving a 3 month mortgage holiday when interest is still accruing on the loan. Also, regardless of what the media or the banks say about affecting the landlord's credit rating, it will still be a black mark against him/her if they ever want to remortgage or borrow in the future. HAP is there for a reason, so the government should use it instead of making it complicated for the landlord and tenant.
Since all the recent job loses and the obvious delay in processing job seeker applications, the government has asked affected employers to pay the employee the equivalent of jobseekers allowance and then claim it back from the government at a later date. They could introduce that for tenants too while the HAP application is going through. So while the tenant is waiting for HAP, the landlords would waiver the rent the tenant owes them, knowing that they can claim it back from the government.