Withholding Rent for Repairs

Rent Arrears

I have a complex situation with a very tricky tenant. I am the landlords Power of Attorney and unfortunatley following an accident he no longer has capcity so I am having to take on the issue.

The tenant has not paid rent for 3 months now and demanding a long list of work carried out on the flat. As the landlord is in recovery (brain injury) he cannot work and the repairs/renovation the tenant is asking for will cost tens of thousands of pounds. 

I have explained the situation as best I can but the tenant is very volitile and quite aggressive and threatening when I try to communicate with him (swearing and shouting) so it is almost impossible to talk to him as he just shouts at me.

Due to the landlords injuries he has also lost his memory so he is not able to confirm any prior agreements he made with the tenant. I have an old tenancy agreement but otherwise not much else in writting.

One major issue is plumbing which is now causing a leak into the flat below however as the tenant is not paying rent the landlord has no funds for the repairs to be carried out. I am now being contacted by the letting agent from the flat below but I do not know what to do. I want to serve a Section 8 but as the leak is now affecting the flat below do I have to carry out the repairs anyway?