Tens of thousands of rail commuters will have to pay more than £5,000 a year for their season tickets after new rises come into effect in January, a union has warned.
The Transport Salaried Staffs Association (TSSA) said people travelling from the counties to London will have to spend more than £100 a week from the new year just to get to work.
The TSSA made the claim as it joined other unions, transport campaigners and rail passenger groups in a day of action to protest at "massive" fare increases and cuts to jobs and services. A series of demonstrations will be held at railway stations across the country to coincide with news of another fare increase.
The Government is allowing train firms to raise regulated fares by 3% more than RPI inflation from January, based on July's inflation figure. Rail unions have warned that some fares could jump by 11% from the new year, while most rush-hour travel, season tickets and off-peak fares will rise by well above the rate of inflation.
Up to 20,000 jobs in the rail industry are at risk under cost-cutting proposals, which will hit station staff, guards, catering and ticket offices, unions said.
Union officials at the protests will step up demands for the railways to be returned to public ownership, saying that privatisation has led to some of the highest fares in Europe despite a massive increase in taxpayer subsidies to the industry.
TSSA leader Manuel Cortes said: "It is complete nonsense to say fares have to rise above inflation every year to pay for new rail projects. Air travellers don't pay higher taxes to get new runways built, and motorists certainly don't pay more for new roads. This is all about squeezing a captive audience, the commuter, until the pips squeak. It is little more than daylight robbery."
Stephen Joseph, chief executive of the Campaign for Better Transport, said: "If the Government sticks by its policy, rail fares will rise three times faster than salaries. With the economy flat-lining, this is untenable."
Protests will be held at more than 40 stations, including Waterloo, Euston and Kings Cross in London, Birmingham New Street, Newcastle upon Tyne, Liverpool Lime Street, Crewe, Glasgow Central and Edinburgh Waverley. Campaigners held up a huge banner at London's Waterloo station, which read: "Cut rail fares, not rail staff."
Reacting to the higher-than-expected 3.2% rise in inflation, Bob Crow, leader of the Rail, Maritime and Transport union said: "This represents a massive blow to the travelling public as they see fares rocket by over 6% in January at a time when household budgets are hit by the Government's austerity programmes. This money will not be invested back in services, it will be trousered by the greedy train operators as another windfall profit."