Are you trying to re-house the travellers again F451! Speak to Basildon Council, their leader has just been nominated for a leadership award!!
By colonies, I take it you mean shanty towns.
(for my tirade against the bedroom tax read "Government wins 'bedroom tax' vote" thread)
I read elsewhere a thoroughly good point, most of these tenants are still going to have to pay their rent, how many will slip into the trap of payday lenders or, worse, loan sharks?
Despite what you say F451, this harks back to my idea of getting rich people to funding housing through tax breaks. Encourage them to invest philanthropically and you could build your shanty towns, only legally and by giving people homes they could really live in.