"These people have been feathering their own nests - literally - and nothing you can say can detract from that."
What, literally? With actual feathers? ;-)
Seriously, though, I think there's a fairly simple remedy, jno. Make the system transparent. When all this dies down, you'd hope people will recognise that many expenses (however expensive they might be) are essential in MPs' line of work, and in making sure it's not a job that's only feasible for the already wealthy.
Once that happens, I'm sure people will tolerate us picking up the tab. We don't need tighter limits on spending - the current rules (as pointed out by ludwig) are fine. Make the system publicly transparent, and MPs will have to be sure their expense claim meets the guidelines, or they'll be answerable to us. Claims that take the p*ss will be exposed. MPs will think twice before they claim for dog food.
And genuine claims will be accepted. If you're racking up �500 a week travel expenses because you're travelling back and forth between Aberdeen and London to represent your contituents, that's one thing. If you're claiming that amount to commute from Henley, you've got explaining to do. I honestly think that most right-minded people are happy to foot the bill for MPs to do their job.