Hi, thanks for your question. Just a bit more information required to fully assist you:
-Where do you live?
-What have the arrangements been for the mother to see them to date?
-Are there any court orders in place, if so what?
Thank you for confirming. Given the issues you raise and the fact that you have brought up the children since birth you would have grounds to pursue an application for a child arrangement order (for residence). You can do this using form C100 and a £215 court fee. As you would not have parental responsibility you would first need permission from the court which is done on the same application and it is likely you would obtain permission given your heavy involvement. Furthermore, you may wish to apply for a prohibited steps order to prevent her leaving the UK with the children given the concerns you have raised.
Initially you should be making a referral to an independent mediator (you can find local ones here: familymediationcouncil.org.uk). The mediator will assist you both in reaching an amicable agreement that is in the children's best interests. However, if there is an immediate risk, mediation will not be required.
For your information the Court will take into consideration the following when making a decision regarding the application:1.The wishes and feelings of the child concerned2. The child’s physical, emotional and educational needs3. The likely effect on the child if circumstances changed as a result of the courts decision4. The child’s age, sex, backgrounds and any other characteristics which will be relevant to the court’s decision5. Any harm the child has suffered or may be at risk of suffering6. Capability of the child’s parents (or any other person the courts find relevant) at meeting the child’s needs7. The powers available to the court in the given proceedingsIf you have any further questions regarding this please let me know. In the meantime if you found this information helpful please provide a positive rating using the stars at the top of this page. I will not be credited for answering your question without a positive rating. Thank you