You still need to establish some facts prior to making an application.
A PSO wouldn''t prevent mum from moving, but it would prevent her from moving your children out of their current location. You would need to prove that moving them away would be detrimental to them, ie:
•The other parent is acting unilaterally, disrupting the children’s well-established routine, and shared parenting with you is being terminated without regard to the children’s best interests;
•The other parent’s relocation will effectively erase you from your children’s life;
•You suspect the other parent’s motives, as there was no discussion with you to seek viable alternatives;
•The other parent has no pressing need to relocate, so you believe it has been done to prevent contact;
•Removal from the area is not in your children’s best interests as they are settled at school and moving them away would interrupt their relationships with teachers, friends, other relatives, and, of course, yourself
However, I don''t wish to get your hopes up as judges don''t like to restrict personal movement of a parent, and your ex may believe that she has a good case in moving your children. The problem with applying for a PSO to restrict internal relocation is that it can be viewed as controlling and with school aged children it is often better to apply for a PSO on the grounds that a change of school and losing friendships would be disruptive. A PSO application won''t necessarily stop the move but court proceedings ensure that proper arrangements are in place before the move takes place.
Your best option is to come to an agreement with your ex - if you present it as a fight, then it will become hostile. You need to present the arguments against her relocation from a child-focused perspective. Booking some
mediation sessions is a good step. It might be an idea to ask her to set out how she thinks contact will work if she does move. How often, who will travel, who will pay for the travel, how will your children cope with the travel, etc.
Another option would be to offer to move to her new area in order to continue with the current arrangements.....
Or for your children to live with you, and Mum has contact on the basis you current have.....