He can stop them moving away if he decides it is unfair to him and stopping him seeing his children.
I went through the same thing with my youngest, though luckily my ex agreed to the move.
Your daughter has to show it is the best interest of the children to make the move [ not her ]. She must have schools in place and a contact agreement to show that she will carry on with access arrangements.
She really needs to get legal advice with a solicitor who deals in this. If she just moves, her ex can take her to court.
Baby Reindeer - anyone watched it?
Alphabetical girls and boys names January 2024