A complicated question, Lou, so I hope you will not mind if the reply is complicated.
I am assuming you are not married and my reply is based on that assumption.
If you are not married the position is governed by general property law. A Court does not have the redistributive powers it does on divorce.
When you bought the property, your shares ought to have been spelled out. The first thing a solicitor will do is to examine the deeds to establish what your shares are.
As a general rule of thumb :
• Where one party is the sole owner of the property, the starting point is exactly that – the owner has 100% rights;
• Where the property is jointly owned the starting point is that the parties own in equal shares.
• If the deeds say that one party owns, say 75% and the other 25% then that is what their shares will be.
• If either party wishes to displace these basic rules the onus is on him/her to demonstrate why.
This is usually achieved by establishing contributions, for example, providing part of the initial deposit, helping with the mortgage, improving the property and so on – but not contributing to household expenses.
Over time, the Courts have used a number of principles with strange sounding names like proprietary estoppel, constructive trusts and resulting trusts. If you think that sounds like a mouthful, you’re right. But the general idea is that it can be possible ( for example ) for someone who is not a legal owner of the
FMH to establish an interest in it by making a contribution towards the deposit, helping out with the mortgage payments, financing improvements to the property and so on ad infinitum. Or, alternatively, if the parties have shares in the FMH of 50%, it could perhaps be altered to 60/40 or some other figure.
In general the law is largely governed, firstly by sections 14 and 15 of the Trusts of Land and Appointment of Trustees Act 1996. This is also a bit of a mouthful, so it’s usually called TOLATA.
Secondly, there have been two very important decisions of the House of Lords ( Supreme Court )
Stack v Dowden
www.familylawweek.co.uk/site.aspx?i=ed749
Kernott v Jones, 2011 UKSC 53.
Well, I warned you it was complicated. You need legal advice and that depends very much on the facts in your individual case.
But as a first step you need to establish who owns the property and in what proportions. This much is relatively easy and not particularly expensive. The problem comes if either of you wants more than the share which exceeds their initial entitlement.
LMM