Train fares could see a 37% increase by the next election, despite the government being warned the move could cost votes.

Ministers are expected to raise the annual cap on fares from one per cent above the retail price index to three per cent, in a bid to cut the national deficit. If this happens then most train fares will be 37 per cent higher by 2015.

The figures were compiled by The Campaign for Better Transport based on official inflation forecasts. A spokesperson said:

“Passengers have been promised ‘fair fares’ by the government, and now many could be paying hundreds, if not thousands, of pounds more.

“We need to encourage more people to take the train, not price those who already do back into their cars.

“We want to see fares brought down gradually to within the European aver­age – at the moment they’re 20 per cent higher.”

Train fares are already due to rise by 5.8 per cent in January and a further hike could cost the government votes.  74 per cent of commuters are less likely to support a party which raises the cap on annual fare increases, according to a YouGov poll.