Hello, my name is XXXXX XXXXX it is my pleasure to assist you with your question today. You certainly have nothing to lose by making them such an offer.
If you have more specific details of why you are not able to pay them in one go then you should make these clear to them and show them that if they were to take enforcement action, they are unlikely to get the money they are after and could just be wasting their time and even more costs in trying. So it would be reasonable to consider a periodic repayment and it would be beneficial to all, the most realistic option and not result in an increase to costs
Please let me know if this has answered your original question or if you need me to clarify anything else for you in relation to this? Thanks