Personally I think MPs should be allowed to go first class, especially for longer distances. Contrary to what people think they are very busy, and I am sure they would welcome the extra space and privacy to be able to use the time effectively, typically on constituency business.
The MP for Penzance will spend around 10 hours a week on GWR, travelling between their constituency and London, and I am sure they could work much more effectively in first.
I think that a better situation would be that MP's get standard class (or first if less expensive) on expenses, then if they wish to go first class, they can pay the difference.
