Enforce a maintenance order

Hello all,
Hopefully someone can help.
We agreed a maintenance agreement and my ex moved to China and has stopped paying and owes over £7000 .
They return 3 times a year and have remarried as they are British not Chinese.
I never never stop access but I feel that I need to enforce the court order.
Issuing a D11 and asking for their passport to be seized on their next visit or their old company pension to be frozen is the only way I can think.
Any help would be great.

Was the order for spousal or child maintenance?

Do they work for a UK company?

The UK has no authority to make foreign courts enforce maintenance orders.

The only exception would be if the order was for child support, and the non-paying parent has moved to one of the countries that has a REMO agreement with the UK. Unfortunately, China isn't a participating country.

Hi I know about China not being in any agreement.
What I want to is enforce the court order so when they visit Ithey can be arrested/have their passport seized .
They have tried to use the legal system here to see the young lad. It was funny as the judge said you get more at the moment than you asking for so why are you wasting our time .
Been advised a D11 needs issuing.

Any court proceedings relating to your child would have been done in the country where he lives, regardless of where the applicant parent lives.

If he has his passport seized, as you would like, he would not be able to return to his job, and therefore not be able to pay any child support at all. Punitive measures such as taking away a passport are done very rarely, and would be done at the discretion of the judge, rather than someone applying to court for that action to happen.