The system clearly needs looking at.
However, it'd be good if envy and bitterness didn't cloud the issue. What I want is MPs to be well-paid - so that we get the best people. Slash their earnings and talented people who might have been considering standing as an MP will choose to work in business instead. We'll be left with a poorer standard of parliamentarian, and a greater class divide: people who are independently wealthy will be able to afford to stand as an MP, those without daddy's inheritance won't.
Like with any job, they should also be paid expenses. If your company wants to go to a conference down south but expects you to pay for the hotel from your own salary, you'd decline to go. Same principle applies. But some of the claims that have been exposed in no way pertain to the job itself. Dog food and tennis court repair are just lauaghable.
As I said on another thread, allow them to claim expenses but put them in the public domain. They'll then have to think twice before claimng for anything frivolous. The press and public will expect them to be able to justify it. Which seems fair to me. If it's reasonable and their job requires them to incur that expense, I'm fine with that.
What we don't want is to penny-pinch. You get the standard of politician you pay for. Skimp on that and we'll see a brain drain away from politics. And we'll have our laws made by people even less talented than the current lot.