Long story, will try not to drip feed.
Ex h and I have 3 DC ages 8 to 14. He drank heavily. We separated 5 years ago.
He went off the rails and introduced the DC to 5 different women in a year and continued to drink heavily and smoke weed.
He then got together with a woman who lives a few hours drive away and settle down, they had a child. DC were devastated when he left but he continued to see them every other weekend.
He would often be abusive to me if he didn't get his way and point blank refuses to co parent with me.
He told me the other week that someone had crashed into his parked car and that he wouldn't be able to have DC for as long as he'd told them he would over Easter and that he'd split up with his gf and had nowhere to stay with DC... He blocked me on the phone when I questioned him(he often does this). I contacted his girlfriend to ask what was going on and the floodgates opened and our text conversation lasted all week.
Basically he's been drinking very heavily and smoking a lot of weed, was caught drink driving after crashing his car really badly (rolled off the road and lost the back end of it!), has been very abusive to her and looks like a heroin addict. He also lies continuously. Over Easter he told 13 year old DD she could have a vape and he'd let her watch game of thrones and other random weird stuff.
The DC have said they think he's 'addcited to alcohol', although he tells them he's now stopped drinking. His GF (now ex) has told me he's started smoking weed heavily and god knows what else.
I've tried to contact him but I'm still blocked on his phone. I do not feel comfortable with him in sole charge of our DC and driving them for hours at a time to his house. Am I within my rights to refuse access until he stops abusing drugs and alcohol? I've told his ex gf that our conversation will remain between us so that makes confronting him more complicated.