Rejected petition vouchers instead of cash for benefit claimants

i would like to pettition the government to make a change in the benefit system. i would like to see vouchers introduced to replace money for benefit claimants as i believe this if managed correctly could prevent claimants from buying drugs and or unhealthy products for themselves and their children. for example colour coded vouchers that would allow for the purchase of fruit and vegetables and prevent the purchase of tobbaco, alchohol and fast food products. vouchers would be non transferable and only used by the indiviual claimant. the vouchers could also be used for clothing and other essential products. i think the main problem in england with the gap between the unemployed and the low earners is quite simple its the cost of living and more over the cost of living in a healthy way. a cashless voucher system would prevent unhealthy living, anti social behaviour and encourage people to find work. government buying power could ensure cheap healthy products for voucher users.