I personally would like to see child maintenance built into the tax system. If it is possible to do this for student loans, It could be done for CM.
The problem is the cake is only so big, whereas the offspring can be effectively infinite. If a man has 10 kids and earns (stop laughing at the back there) £1,000 a month, then how much does each child get ?
Or if he's on benefits - which as we know are already below the bare minimum - how do we extract the necessary 10xwhatever from his £72/week ?
It's a shame we can't remove boys testicles at birth, keep them in a vault, and then let them out once we know he's going to pay for his fucking children. But you'd need the staff. And given the mindboggling levels of incompetence currently on show from the government, I wouldn't trust them not to lose them and joke about it being a cock-up in the same press release.