There's much discussion about how much space and other 'treats' posters expect to get with first class travel compared with standard class. All of these enhancements come at a cost that should only be borne by those passengers benefiting from them. For instance, the current cost ratio of first to standard fares is about 1.6:1. Therefore if an inter-city coach seats 80 passengers in full standard class configuration, it would seat 50 passengers when configured for all 1st class.
Furthermore, if all theseadditional 'luxury' enticements such as complementary food and drink, wi-fi, better quality seats, and station lounges are part of the offer, the cost of providing them should also be covered by the additional cost of the ticket. It is already likely that despite the enhanced travel comforts that come with first class, standard class passengers may have to travel in coaches loaded above their seating capacity, so any fare structure that expects them to subsidise first class travel would be unacceptable. Similarly, any expectation that public funds subsidises those privileged travellers would also be unacceptable.