They could put a heck of alot more by shaving a fraction of a %age of tax that the companies pay.
The announcement is more of a 'look what we're doing' than anything else.
The majority of the bandwidth there going to save is going to be by allow the isps to curb the rest of us. That I feel is already in place.
In regards to MPs claiming expenses, I don't blame any of them. The rules were there as they exist, and they made claims accordingly. Those who either made the rules or passed the claims are the ones who need to re-adjust their rules or not be so flexible.