Consider, payment level would be determined by court/CSA and failure to make full financial disclosure would result in seizure of assets/passport.
Once payment level is determined, missing a payment because "I'm a bit short this month/ I'm getting married and the wedding is expensive/I've got my holiday or new car to pay for", just means that a debt is accumulated with interest being added.
You want to bum around hiding your true income level for the next ? years until all the children are beyond the age for CSA etc, fine, but you'll just end up paying the debt later and it will have increased by the interest charges added.
Obviously the situation would need revising where you could prove loss of employment for a period of time etc. to match the financial circumstances your partner and kids would have been in had you still been together when redundancy happened.
Surely there's something to be said for looking into this (and excluding CSA debt from being wiped out by bankruptcy too).
Can someone please (tactfully) point out the flaws in my argument before I write to my MP and suggest it (tongue in cheek emoticon).