Before Mrs.Nhengu (Gamu's mother) and her family leave the UK voluntarily I think it would be great idea for David Cameron to meet her and have a look at her completed benefit application forms for Child Tax Credit & Working Tax Credit. According to news reports Mrs.Nhengu has broken immigration rules by claiming these benefits she was not entitled to and has to leave the UK.
If Mr.Cameron could just have a quick look at some of these forms it might give him an idea on how this is happening and how easy it is for people from overseas to play the system, it could prevent other false claimants in the future and save the UK tax payer thousands or millions of pounds.