Do not listen to his lies.
Do not move out.
Ask your brother to contact him DIRECTLY and univite him.
Any drama that happens record it.
More proof of his unreasonable behaviour.
He is a desperate violent man.
Any hint of violence ring the police.
Do not allow him to control you via the children.
He can say whatever he likes to the children, anything.
Keep replying very calmly "that isn't true what Dad said, Mummy and Daddy are not going to live together anymore"...on a loop.
Deny whatever he says calmly on a loop with "that is not true" and move on.
Let the children see his bad behaviour but you being calm.
Let him tell his lies but all correspondence should be through the solicitor.
Let him get more angry and frustrated but the first sign of aggression ring the police and have him removed because he has been violent before and you are afraid.
Remaining calm is your friend.
Ifvyou can quietly safely record him, do.
Make sure your passwords are locked down.
You can do this.