Mortgage reposession adice

I'm new to the forum and hoping someone can help me with a few things.

I took out a joint mortgage with my previous partner. We have been separated for a couple of years (he was abusive) and he is still living at the mortgaged property alone.

I have recently been contacted by the mortgage company to tell me that he hasn't been paying the monthly installments. I don't have access to the property, but the mortgage company have now come to me to pay the bill.

In the long term I don't want to be responsible for the property as I don't live there, don't have access to it and don't have contact with my previous partner. The only communication we have is via a solicitor . The property is currently on the market and I know it's likely to be in negative equity.

My reason for posting is, I would like to know if anyone can give me any advice about letting the mortgage company repossess the property.

Am I likely to be troubled by a debt collection agency personally and will this have a negative impact on my credit rating?

Any help or advice would be appreciated because I don't know where to turn and I have only a couple of weeks left until the mortgage company reposess.

Thanks in advance.