It is effectively true. Many European firms own chunks of the rail franchises in the UK and charge a shed load more than their local rail services are able to. Similar to the power franchises with the likes of EDF owning a large stake and charging a lot more here than they can get away with in France.

It isn't an EU thing, though it has at times been something Farage and his ilk have banged on about as if it is an EU thing, it is the way the Tories setup the privatisation of the railways (running them into the ground first as part of making the case for taking them away from the public purse (which it isn't as there are still significant subsidies involved)).