Joint Mortgage Sole Occupier -can a sale be forced by the non occupier?

AndrewXX

I agreed to a joint mortgage to help a relative who is the sole occupier of the flat. Almost immediately he stopped the Direct Debit and paying the mortgage. I have only found out and paid 5 months arrears. Is it possible for me to force my relative to sell the property which it appears he does not intend to pay for? (He could initially afford to pay the mortgage  but I have discovered he has since made foolish lifestyle choices and has accrued additional debt - and by paying for the roof over his head I am enabling him to continue in a lifestyle that is damaging his health. He won't be penniless as he had a 50% deposit on the mortgage but he is unlikely to volunteer to sell as our credit rating has been damaged and he won't be able to get another mortgage). Advice welcome.

getmore4less

What agreement did you set up(usually a trust deed) to cover this arrangement?
would have things like
The won't pay cant pay scenario you are in if you pay(do you get a beneficial interest or does it create a debt)
Can the place be let out and the proprietor move out.
Events that trigger a sale/repayment  like won't pay or they move a partner or they die
 

AndrewXX

I do not have a trust deed. My independent financial advisor didn't even suggest one or tell me I should have a legal exit plan. 

TrickyDicky101

Did you take independent legal advice?  
You are jointly and severally liable for the whole of the mortgage (which I suspect you know given you have paid off the arrears).  If he fails to pay and if you don't either the bank will ultimately take action to recover the debt.  Unfortunately for you, this doesn't necessarily mean they will go after the security (ie the flat) if they see you and your assets as an easier mark.  Your credit records would also be trashed in the process.