Non-resident parents who fail to pay child maintenance should be criminalised.

Non-resident parents with the financial means who repeatedly fail to financially support their child/ren should be prosecuted for child neglect.
Failure to contribute towards housing,clothing and feeding your child/ren constitutes child abuse and should be criminalised accordingly.

It is already possible for people who don't pay child maintenance to be sent to prison for non-payment, or to have deductions taken from their bank account, their earnings or from their benefits. There is more information about this here:

https://www.citizensadvice.org.uk/relationships/children-and-young-people/child-maintenance/child-maintenance-2012-scheme/child-maintenance-enforcement/child-maintenance-enforcement-where-to-start/

If you could be more specific about the change that you would like to see, you could start a new petition.