Legal position regarding mortgage?

Right this is complicated, so please bear with me.

Almost two years ago I suggested to my ex husband that if he paid for the cost of it and took my name off the deeds and mortgage of the house, I would be prepared to walk away from our marital home with nothing. He agreed to this and put the wheels in motion, so I have in my file a letter from his solicitor asking me to confirm that I was in agreement to this, but this is all I have in relation to it.

My ex has always been atrocious with his finances, and has a real debt problem whereby he constantly spends beyond his means and has remortgaged several times to repay his credit cards and overdrafts when they become unmanageable - this is one of the reasons I walked away from the house, it has no equity left in it and wasn't selling, and to be honest I needed to make a clean break before he dragged me down with his debts again.

Our divorce was finalised in October this year - 18months AFTER I left the marital home, he had by this point moved his new partner in the house. He hasn't however, managed to secure a new mortgage in his name, removing mine from the loop to so speak.

This year he's apparently had to take a pay cut (but he was already on £70k+ per annum), however, he's still decorated most of the house with his new partner, including new carpets an furniture and not just a fresh lick of paint, but it appears that he has money flow problems again (my 17 year old daughter informed me last night that he's trying to borrow £200 from her).

My worry, and therefore my question is this ... what is my legal position and responsibility for his debts (ie the £240k mortgage and millstone of a house) if he ends up in the proverbial again with his finances? Bearing in mind that I left it almost two years ago, and his new partner moved in 6 months ago, and I'd already asked him to take my name off the deeds and mortgage?

I'm expecting most of you to say go see a solicitor - which I'm intending to do in the new year, but could do with some idea of my position BEFORE then. So any solicitors reading this section ...