I heard an even harsher suggestion - if after 2 kids you cannot afford more without State help, they should be sent for adoption rather than the state paying. This is not, not, my view, but a hard liner I know expressed it as a deterrent to the type of parent refered to by Kevescar
Adoption would equal more revenue being spent in the wrong direction. As an example, look at what it is suppose to cost to house a young offender per week, or even a person in other forms of institutions.
Child benefits were brought in to help families in the times of national need, but now there are ways to self support if you have the inclination to do so. The people who are the biggest offender's are those that have never considered supporting themselves or their future offspring, and have perhaps been educated that way, both by their own family or the state. Perhaps now is the time for compulsory re-education?.
Just stop paying people to produce children. A fixed rate of benefit regardless of circumstance. No jumping up the housing ladder because you have children. Want to smoke, have sky tv, several dogs or other luxury's: work for it. Unless your a government buying votes.
"and stop the single mums having loads of kids to up the benefits"
No it would not. Child benefit is a deductible income source. If someone gets an entitlement of £100 a week on income support, the child benefit is classed as income and is deducted from that £100. So a single mother would get £80 income support plus the £20 child benefit.
If you stopped child benefit 100%. The state would pay her £100 in income support.
So to those who receive income support, child benefit does not matter. What they may loose on the swings, they claw back through income support.