As the average wage is £24000 per annum (Gov Figures), and this country is is debt, I suggest the following:
Any family that is on benefits is restricted to 35% of the average wage (£161.54) per week, which includes all benefits (cash and kind -- rates, rent, furniture allowence etc)plus family allowance for the first 2 children only (£20 + £13.20)making a living allowence of £193.73.
By the time you add the Income tax & Nation Insurance you would have paid, this works out to the equivilent of approx £1242 or £276.11 per week.
I believe that is fair-- Your comments please. Terry