The courts will expect you to try and work this out with your ex-partner through mediation however in practice, if a Mother is already not supporting your contact then mediation is unlikely to work.  You should know though that the court may hold up any application you make until you have tried mediation or attended some other programme, such as Seperated Parents Programme.

Ultimately you may well find yourself needing to make an application to the court by way of a C100 form supported by a C1A form if there is a concern around your children being harmed.

You can do this yourself or you can get a solicitor to help you prepare the forms.