I think change is possible but over 30 years of privatisation have completely fragmented the system. It'll take a long time to Humpty back together again and probably most the bandwidth of the transport civil servants too. The real risk is we could spend another generation trying to untangle the privatisation web only to find by the time we're finished doing that as a nation we're now the proud owners of a completely obsolete train set.
Any party that promises to bring back trains with proper restaurant carriages with real table cloths and cutlery that serve a full English breakfast will get my vote
