Apparently Gordon Brown is clamping down on M.P.s' expenses. It's good to see the executive branch fulfilling its traditional role of holding Parliament to account, particularly on spending matters.
Actually that sounds slightly odd somehow... well, whatever.
Being serious, I think M.P.s turn to shameless looting as they come to terms with their dwindling influence. It's not that they're completely powerless. If that were the case they would have nothing to lose by actually taking a principled stand against the government, and might cause some actual disturbance. But as we know, the job of the civil service is to make sure the chips stay up, and M.P.s are left with just enough power to keep them playing. However, this is not enough to justify having devoted one's life to climbing the greasy pole, so they satisfy themselves with mere money.