Please help, advice needed

Good morning all,

Was hoping someone could advise me appropriately.

I hqave two teenage daughters aged 13 and 16, myself and the wife split up in november due to her having an affair. She is still with this guy and both of my daughters have taken a dislike to him and do not want to get to know him. Last night i was contacted by my youngest daughter very upset as her mum had allowed this new guy to stay overnight although my daughter had already told her mum she didnt want him there and that she felt uncomfortable with him in the house.

I have also discovered that her new partner has criminal convictions and has completed 2 stretches in prison for violence, gbh and threats to kill.

Both of my girls have told their mum it is too soon and they do not want him in the house, my eldest is also aware of his criminal past and it makes her very uncomfortable.

I am extremely upset with my ex wife about this as she assured me 3 weeks ago she would not be allowing him into the house etc until my girls felt ready, she has now gone against this and my youngest told me that they were both extremely drunk when they came home last night and that she was frightened to confront her mum about it as he was stood next to her.

Can i approach a solicitor and get an order to keep him away from their house and from them considering he has previous for violence etc.

Any help would be great.I have a responsibility to my kids and they are looking for my support on this.