What is the likely outcome of custody arrangement with my abusive ex spouse of our 1 year old? England/Scotland

Essentially my husband mentally and emotionally abused me for years and has started physically abusing our 1 year old by pulling hair out of his head and dragging him around. He has admitted this and contacted a domestic abuse intervention programme but hasn’t signed up or started yet.

I’ve left the family home in England to stay with my family in Scotland with our son because I didn’t think it was safe.

Would he be able to apply for custody of our son when we divorce? I’m terrified that he would be able to get unsupervised access to him.