Rail fares in the UK are set to rise by up to 2.8% from January, adding as much as £100 to some annual tickets.
Regulated rail fares and increases are based on the Retail Prices Index (RPI) measure of inflation for July, which was 2.8%. However, passengers and organisations have called for the more commonly used and accepted Consumers Prices Index to be used. In July, it was 2% and is typically lower than RPI.
The Campaign for Better Transport (CBT) described rail fare prices as "exorbitant". Chief executive Darren Shirley said: "The government should commit now to January's fares rise being linked to CPI."
Rail Minister Chris Heaton-Harris said: "It's tempting to suggest fares should never rise. However, the truth is that if we stop investing in our railway, then we will never see it improved."
The TUC renewed its call for the UK's railways to be renationalised. General secretary Frances O'Grady said: "We're already paying the highest ticket prices in Europe to travel on overcrowded and understaffed trains.
"The number one priority should be running a world-class railway service, not subsidising private train companies."