Equity claim

[user1489434024]

Can an ex partner make a claim on equity when they haven't paid towards the joint mortgage not lived in the property for many years? They've also expressed that they do not wish to pursue it but looks like changing their mind.

My understanding is that they can. While they haven’t paid the mortgage, they presumably haven’t had the benefit of living in the property either.
I was told that if half of the mortgage was paid by the ex, then the person living in the property would be liable to pay rent on the ex’s half, so the payments are effectively cancelled out.
Is the property owned as joint tenants or tenants in common?

Yes I think probably they can. A number of points. Were they married. Is the house in joint names. Was it the marital home. What did the divorce settlement say. I don't think not contributing to a mortgage means there is no claim. And not living in the property wouldn't rule out a claim AFAIK.