Given the fact that they keeping batting this back to you, I think they are just being cheeky fuckers. So I wouldn’t bite. If they actually needed a rent reduction, they would do as you ask.
However.....circumstances change so I would leave things open with them.
Dear Tenants,
Further to our previous conversation, I am willing to consider a rent reduction if you have been adversely affected by Covid-19.
As you are aware, when you took on this property, you had to supply evidence of affordability such as pay slips, bank statements etc [OP - it is worth double checking what they did provide so you can ask for same again or similar].
In order for me to review your rent, please could you provide your P45 or evidence of any salary reductions or evidence of benefits along with your proposed terms for a rent reduction.
I understand that these are difficult time so will get back to you as soon as possible after receiving the documentation. I am also open to reviewing this on a regular basis as events unfold. I look forward to hearing from you.
Yours sincerely,
Lovely Landlord
I also think calling them is a good idea but follow up any conversation in writing to cover yourself. Something along the lines of ‘ I am writing to confirm that you said x and I said y and we are doing z).
My own, personal view - proportionality is everything. If they have 20% less income (and were good tenants), I would give them a 20% break if I could afford to. I would also be open to their suggestions of (a little) more than that as housing is a big cost and not all other expenses can be reduced by 20%.
That said, people on furlough will no longer be spending as much on work related expenses such as tube tickets/petrol/parking/coffees/ clothes/dry cleaning etc. In fact, when you consider retirement advice Regarding the income you need when working and when you retire (ie are not working), the amount goes down by 20-40% depending on which calculator you use.