Transport secretary Chris Grayling has called for future rail fare and wage hikes to be based on the lower Consumer Prices Index (CPI) rather than the Retail Prices Index (RPI) which is now used to adjust regulated fares every January.
However the rail unions are refusing to use the lower level of inflation to set pay rises for staff.
The Rail, Maritime and Transport (RMT) union accused Mr Grayling of trying to cap pay rises and blame workers for high fares.
PASSENGERS could be priced out of travelling on Scotland's railways when peak fares increase 3.2% next year, Scottish Labour have warned.
He added: If the Secretary of State recognises that train companies' profits are responsible for sky-high fares, instead of asking them to make less money, why not go one step further and end privatisation altogether?
Inflation figures will be published on Wednesday, leading to controversy over whether fares should increase at all given the disruption faced by passengers in recent months.More news: Trump administration sanctions companies helping N Korea
Mick Cash, general secretary of the RMT, said: "Despite all the timetable chaos and service and staff cuts our rail fares are up to 5 times more than fares in Europe and are rising twice as fast as wages".
This means a commuter travelling from Brighton to Victoria will pay almost £4,471 as part of their annual season ticket, up from £4,332.
Jeremy Corbyn has slammed train fare hikes as an "insult" to commuters across Britain who are suffering due to the government's "shambolic mismanagement" of the railways.
Protests around the country are set to go ahead amid frustration over an expected 3.5% increase in train fares as a result of using RPI. See story RAIL Fares.
"After a torrid summer, passengers hit by the timetable crisis will be amazed that the talk is about a fares increase!"
However, campaign groups argue the bigger problem is using RPI as the index to set prices rather than the Consumer Prices Index (CPI) measure of inflation, now 2.5%. The men and women who run the railway are being singled out while greedy train companies are let off the hook yet again.More news: Shearer predicts how Mourinho's 'row' with Pogba will end
Andy McDonald, shadow transport secretary, said: "The amount by which train companies can raise regulated fares is the responsibility of the Transport Secretary".
Season tickets on most commuter routes, some off-peak return tickets on long-distance journeys and Anytime tickets around major cities.
But Pressure group Railfuture claimed train passengers are being treated like "second-class citizens compared to motorists".
GMB general secretary Tim Roache said: "Millions of passengers face a grim start to the new year when they are forced to pay even more extortionate prices for a frankly shocking service from the privatised rail companies".
"We're investing heavily in improving the reliability of our existing trains, upgrading stations, making ticket purchase simpler and easier, improving auto parks and raising customer service standards, to ensure that our customers get the best possible value for money".
The figures show that rail fares have risen by 42% over the past ten years, while nominal weekly earnings have only grown by 18%.More news: Explosion in Yemen's Aden targets provincial governor's convoy
Commuters that must buy a season ticket to get to work will be hit the hardest by the hikes according to passenger groups.