There is a very simple answer to the long-running soap-opera over MPs' pay and expenses. Stop paying them salaries and expenses – and pensions. Instead, treat them like the adults that some claim to be.
Pay each an annual "constituency fee" and let them decide how to spend it, whether on themselves, staff, offices or whatever. Require them to publish annual, audited accounts on their websites and a summary on their electoral addresses if they stand for re-election. Let the voters then decide whether their MPs are value for money.
The "fee" would be equivalent to the combined total of pay and expenses, currently in the order of £200,000 a year. If they decide to pay themselves the whole amount to themselves in salary, fine. Let them answer to the voters – and the media. But also include a "recall" provision whereby, say, ten thousand voters in any constituency can demand a re-election at any time, to oust someone who is abusing the system.
Then, get rid of all the "privilege" committees, pay reviews, etc., and focus on what MPs actually do for their money. That is where the emphasis should lie.