Who on earth mentioned benefit fraud? I don't think that's relevant to this conversation.
The problem with a living wage is that it won't remain a living wage for long if you have plenty of people who are willing to work for it. It would be a green light for private landlords to put up rental prices which would hit the working poor hardest, the people who have never been able to save for their own home because they live hand to mouth, but have never gone down the route of social housing because they've always had just enough money to keep them going down the route of homelessness. Inflation would go up, supermarkets and fuel companies would put up their prices and it would essentially become meaningless and just the same as the minimum wage and just another meaningless line in the sand which didn't guarantee any sort of decent life.
The only way to make the life of the working poor better is to stop the flow of unlimited cheap labour which is suppressing wages. We need some to fill gaps, but not the unlimited flow we have at the moment. It's not just unskilled jobs either, jobs like building, mechanics, accountancy and secretarial administration which all used to provide a decent standard of living pay little more than poverty wages these days. I don't believe the lie that there are jobs that British workers 'won't do', I think it's just that there are jobs British people can't afford to do. After all, if you are a Hungarian who is coming over to work here for two years you may well find it acceptable for 2 years to live six to a room and work 12 hour shifts six days a week. But if you are British and it's not just something you're doing temporarily, it's your whole life for the foreseeable future, that's just not acceptable.
We don't invest in our young people any more because it's cheaper to bring in someone trained elsewhere so they are left languishing jobless. It's unacceptable to advocate mass immigration when we have a youth unemployment problem.
The £20 billion figure also doesn't take into account all the tax credits and housing benefit which is being paid out due to low pay. Until the flow of cheap labour stops life is never going to improve for anybody but the middle classes.
Labour are not and cannot be the party of the working class while they support mass immigration. They are doing the most harm to the people they are supposed to represent. Labour is the party of wealthy university educated middle class people who have benefited from cheap labour with their nannies, cleaners, gardeners and au pairs. They are not the party of the working class.
Unfortunately nobody else has stepped into the breech they've left behind for the working class. Although UKIP want to stop mass immigration their economic policies would be catastrophic for the working class. Labour has left the working classes basically totally disenfranchised. Nobody represents their interests.