50/50 once each party has their deposit returned. I hate to see what you pair are going to be like when you have to buy your first pack of binliners.
You're really making your simple house purchase with a quest to complete by June massively overcomplicated.
This pretty much.
Swear there's a section that says person A's deposit, person B's deposit, how is the property owned 'shared/equally/split' or whatever. Your solicitor or mortgage advisor even may be able to help.
Cant recall what I put as a deposit but it was more than the wife, if we split it's 50/50 regardless the way I see it....hell I'm currently shelling out redoing the garden, wife can't afford the excess from wages so I'm paying for it, doesn't mean I go 'oh I spent x on the garden and increased the house value by y percent so gimme moarrrr'

If you're bothered, get a prenup or whatever it's called.