My son is 5 years old and me and his father have been seperated for last 4 years i have a partner who has been involved in his life for the last 4 years but he also sees his biological dad every weekend. (thats the background done) I have a 7yr old daughter who has a different father than my son and she wants to change her surname to my partners as well as change my surname to my partners. My daughters father has no PR so i can do this without his consent however i want to change my sons and his father is not happy about it and refusing as he has PR. The issue i have is that both my children have my surname but my sons name is double barrelled without the hyphen with his fathers surname and my surname..i want to change my surname to my partners and keep the biological link with his father there but my ex partner does not see it that way he is just refusing point blank to let me change my sons surname which is my surname. I would take him to court myself without the help of solicitor but im wondering if its going to be worth it in the end or am i fighting a losing battle?....