I'm after some advice really.
The back story is this. I met my partner who has 2 boys aged 9 and 14 4 years ago. I have a son who is 7. My partner left her boys father within a year of the youngest being born. He was incredibly controlling and ground her down. He was a policeman and it's quite a common trait apparently. He has tried to destroy her. She had a total breakdown whilst with him and he turned his back on her and tried to get her sectioned and the kids away from her. But she got her life together, got a small house and moved on. He also moved on and married someone. The court ordered 50/50 custody based around his working shift pattern in the police, which meant the pattern was very haphazard which meant the boys were never in to a settled pattern. When the boys were in his care they weren't allowed to mention their Mum and certainly never allowed to miss her. He would go through their phones and ipads to ensure if there was any contact with Mum whilst they were with him, he could monitor the messages. This continued until the eldest boy became of an age whereby he can make his own decisions. He now only goes to his Dads sporadically which his Dad is convinced is because is Mum has brainwashed him and not because of his actions.
Now, the youngest (9 year old) is in a very difficult position and has been for over a year now. He wants to live with us predominently and see his Dad less frequently. This is not about getting at another father - far from it. However Dad does not have the best interest of the son at the forefront of his mind. It's all about not letting the ex win. So he feeds him junk food which is causing weight gain. He tells him he shouldn't miss his Mum. He (the son) is struggling with some behavioural issues linked with mental health issues. This has been recognised by professionals and he is getting help for the behaviour, separation anxiety and general anxiety. Dad says there's nothing wrong because his son doesn't display these behaviours in front of him. This is because he puts on a show because he is scared of his Dad. We have now told Dad that his son is seeing a psychologist, the school mental health nurse and a CAMS specialist to try and get him 'fixed' and the help that he needs. Because Dad doesn't believe in mental health or that his son has any problems and is now trying to prevent any of this from happening despite the professionals promoting these treatments. We didn't inform him of the treatments that we had managed to secure for this very reason until now.
As an example of how controlling Dad is, the boy has recently joined a football team. When in his Dads care, he still wanted myself and Mum to come and watch him train. We did this and kept a respectful distance and only waved when the boy waved at us. Later that day a message followed from Dad saying that if we go again in his time, he'll pull the boy from the team and take him elsewhere. This is about getting at his Mum and using the boy as a weapon. His son wants both parents to watch him at his new venture...nothing more. The Dad is an emotionless robot, in my opinion. He only looks to serve himself and not the kids.
My question is, can the boy be withdrawn from the 50/50 court order on the basis that it is the boys mental health best interests not to go there. If this can be done, how would one go about it without using costly solicitors? If further info is required, please let me know and I'll elaborate.
Any help will be greatly appreciated.