This happens with all monopolies, and this government has allowed Sky to get away with it. Unfortunately, it's doubtful if the EU will do anything about it.
Sky have kept out all of the other players due to the specification of their dodgybox, and its severe limitations, as well as the move to Astra 2 for its digital platform. This was compounded by the terrestrial channels joining Sky on the Astra 2 satellite.
It remains to be seen if the breakaway by the BBC will result in a crack in the monopoly.