They haven't been done for fiddling their expense accounts, they have been done for fraud which is entirely different. Many of the dubious practices which some our MPs did were entirely within the rules. Though flipping their property was obviously wrong, it was not illegal. for that reason, I suspect that no others will be prosecuted.
There are clear rules about who is entitled to legal aid. If they are entitled, then they should get it. It is not granted on the public's opinion of the crimes and the people suspected of committing them.