Divorce in England financially splitting the house

Engaged February 2024
The house was purchased in May 2024
Separated June 2026
No children

I paid £100k towards the deposit of the house and the rest of the house was mortgaged.

Mortgage payments were roughly shared however I paid £100 more on a monthly basis.

Bills were shared evenly.

My ex believes they are entitled to 50:50 of the house including my deposit.

Please advise whether this should go to court or what I should do?