As I understand it, they are going to be given work whilst on benefits. Their benefit rate will not increase, but they will be contributing towards the community.
In my mind, this is a good thing. After all, these people would be claiming benefits anyway, so let them do a job rather than claiming for nothing. It's not actually going to cost the country any more than it is now, and there might not be suitable permanent employment, but it's giving the country something for the money that we put in to the system.
I'm sure most of us know of a public area, park, beach, playing field etc, that could do with maintenance. Why not let those already receiving government money (in the form of benefits) earn it for a change!!