Child support second charge

What is the current state of thinking about the efficacy of a second charge against the former matrimonial home under a financial remedies order where the resident parent is agreeing not to claim child support in return for preserving the property and the non-resident parent wishes to ensure he does not suffer double jeopardy? The charge would be for a sum equivalent to any child support the non-resident parent ends up having to pay.

Any agreement not to claim child maintenance or to repay any sums paid under a maintenance calculation would be unenforceable on public policy grounds. While parties are free to agree whatever financial arrangement they wish, we suggest the court should not give its approval to such an arrangement and that the charge would be set aside on challenge.