UK commuters are spending far more of their salaries on rail fares than some European passengers, according to the TUC-organised Action for Rail (AfR) group.
The group, which includes rail unions, said it had compared compared UK average earnings with season tickets covering similar commuter routes across Europe.
Taking into account fare increases, the analysis gives the example of UK workers on an average salary who are now spending nearly 14% of their monthly wages on a £299 monthly season ticket from St Albans in Hertfordshire to St Pancras station in London.
The AfR said that in Europe workers making similar journeys in Germany and France spend around 4% of their salary on train fares, in Spain 3% and in Italy just 1%.
The AfR analysis comes at a time when rail campaigners and some MPs are calling for a rethink over how Britain's railways are run
The AfR said more than 50 Labour, Liberal Democrat, Green, Plaid Cymru and SNP MPs have signed a parliamentary motion calling for the renationalisation of the UK's railways.
AfR believes that high rail fares in the UK are in part down to the additional costs of rail privatisation.
With season ticket fares rising by an average of 3.1% today, rail campaigners, passengers and rail unions will be at King's Cross mainline station in London handing out mock tickets to passengers, which highlight the costs of fares and privatisation and call for public ownership of the railways.
Protesters will be joined at King's Cross by Aslef train drivers' union leader Mick Whelan and by RMT transport union leader Bob Crow.
TUC general secretary Frances O'Grady said: "Rail passengers and taxpayers are being poorly served by a privatised rail service that has failed to deliver any of the efficiency, investment and cost savings that privatisation cheerleaders promised.
"While the shareholders of the private train operating companies are doing well for themselves on the back of massive public subsidies, passengers are paying the highest share of their wages on rail fares in Europe. Rail passengers must wonder why they can't have the same cheap and more efficiently run state rail services that exist elsewhere in Europe."