If you divorce then the length of your marriage for settlement purposes shall be taken to be the full length of your marriage and thus is classed as a "long" marriage. This means that all assets acquired before and after the relationship would be included in the matrimonial assets pool for settlement.
The deposit you used for your current property would simply form part of the asset pool.
There is a presumption that each party has a 50% share of the matrimonial asset pool, but in your case if one person was to having residence of the children then that person would receive a greater share of the asset pool.
If you simply split up with a view to selling the house but not divorcing then there is a presumption (in the absence of any trust document specifically declaring your respective percentage interests) that you both own 50% of the property and have a 50% share in the proceeds of sale. This can be rebutted where one party has contributed more to the intial financing of the purchase (which you have), but you may incur legal fees in establishing this.
Practically if you were to do this then your wife would probably just issue divorce proceedings and seek financial settlement in her favour as above.
Sorry it could not be better news, it's a product of being (or being treated as being) married for a long time.
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