New year rail fare rises will be announced later today, with some commuters likely to have to fork out for increases of up to 10%.
The existing annual price rise formula means that regulated fares - which include season tickets - will rise by 5.8% in January 2011.
But this is only an average figure, with some fares expected to go up by much more than 5.8%.
Passengers will also learn today just how much more they will have to pay for unregulated fares - typically the off-peak services - which have no annual price cap.
And further misery will await passengers in January 2012 when the annual price rise formula changes from the current RPI (retail price index) inflation plus 1% to RPI plus 3%.
Gerry Doherty, leaders of the TSSA transport union, said: "It will be outrageous if commuters are forced to accept massive fare increases when workers across the country are having their pay frozen and are suffering job losses.
"This will be seen as sick joke as we have the most expensive and overcrowded railways in Europe."