Hello and thank you for your question. I will be very pleased to assist you. I'm a practising lawyer in England with over 10 years experience.
May I clarify are you a Regulated or Assured tenant please? If you are not sure when did you move in?
Thank you. These circumstances would not amount to a sitting tenancy. In these circumstances you would have an assured shorthold periodic tenancy under the provisions of the Housing Act. Unfortunately this type of tenancy has no long term security of tenure and the landlord is able to give you 2 months notice to vacate and can then apply for possession through the courts.
Accordingly an offer of £10K is likely to be a very good offer to vacate given that the landlord can serve 2 months notice at any time. There are certain rules he has to follow in giving you two months notice - he must serve notice on a prescribed s21 notice and give you not less than 2 months notice ending the day before rent is payable but subject to these requirements he could recover possession of the property relatively swiftly.
You could string it out through the courts for another 2-3 months optimistically but that is likely to be the best case scenario. If he is keen to recover possession more quickly than this he will have to come to an arrangement with you.
Unless you think with your knowledge of his circumstances (e.g. he has a buyer for the property who requires a quick completion) you can negotiate more thatn the £10K offered in light of the above, my initial reaction is that the amount offered is worth considering.
Can I help you with anything else or has the above answered your questions satisfactorily?
A pleasure. I hope you manage to agree a payment you are happy with be it £10K or more.