Trinpy, I would like it to be the whole govt.
There is a book by Rawls called "A theory of justice". Basically the idea is that if you got the decision makers of society to make the decisions about how society would work while having no idea what position they themselves would hold in that society they would go for something Rawls called "maxi-min" - they would maximise the well-being of the worst-off. You could still have rich people or even a few insanely rich people, but if you didn't know what situation you were going to land in, you would hedge your bets and make sure that all situations were at least reasonably alright.
I think we should actively apply this principle to the govt. I think we should force them all to live for reasonable periods of time under the conditions that they impose on others. As other posters have said, they should still work and maintain their other obligations while living on £54 a week. Let them try to squeeze the last bit of glue out of the tube to mend their broken shoes in the middle of the night, hoping it will dry by the morning in time for work; let them do this while the baby is teething and they can't afford the usual staff, and they have work in the morning; let them do everything they have to do with no cabs, no money to eat out, not even to grab a ready made sandwich or coffee, no paid help, hardly any proper protein. Let them do it.