"How is it fraud?"
If I submit an expenses , housing benefit, income support or tax refund claim in which I claim I am living somwhere other than where I really live, then it is fraud. The government's own adverts show how people claiming benefits when they cohabit with someone who is working should be shopped by their neighbours and then go to prison. Why not an MP who has fraudulently claimed so much more and avoided so much tax?
If I take a job at 60K with some expenses for travel and staying away from home, you can bet the taxman will do their utmost to charge tax on the expenses. I will have to keep receipts and justify everything. If my empoyer finds I have been lying to increase my expenses, I can expect to get sacked - if it runs into thousands, I can also expect a visit from the Police.
Also, since when has it been OK to give jobs paid from public funds to family members? It isn't allowed in the Civil Service - why is it somehow OK for MPs to "employ" a member of their family, who doesn't even posses the relevant qualifications and experience for job in question?
While we're at it, lets have a look at the make up of parliamentary committees - some of these seem to employ MPs mates, wifes and other relatives, most of whom have no expertise in the topic concerned. Where is the oversight?