CASH-strapped commuters across Hampshire are learning today just how much more they will have to pay for their rail season tickets in the new year, with some travellers facing possible 5.1 per cent rises.

Recent government announcements have meant the annual rise in regulated fares, which include season tickets, will not be so severe for 2014.

But the new price-rise formula, which will kick in on January 2, still allows for average regulated fare increases of 3.1 per cent, with the rise linked to the RPI inflation figure rather than the usually-lower CPI inflation used for Government benefits.

And train companies can use a 2.0 per cent ''flex'' regulation which lets them put some regulated fares up by 5.1 per cent as long as their overall average does not exceed 3.1 per cent.

The increase for any January is calculated from the RPI rate of inflation figure for the previous July. In July this year the RPI figure was 3.1 per cent.

Campaign for Better Transport chief executive Stephen Joseph said: ''Passengers will see season tickets going up three times faster than their wages.

''The Government needs to do more to stop the squeeze on commuters and avoid pricing people off the railways. We need a permanent end to inflation-busting fare rises calculated using an out-of-date formula.''

He went on: ''The Government should stop using RPI to calculate ticket prices. It over-estimates real inflation so consistently that the Office for National Statistics has dropped it as an official measure.

''The Government has already switched to CPI for most things. Doing the same for train fares would have little impact on railway revenues, but it would save passengers money and bring fares into line with things like public sector pensions.''

The announcement of the rise has been delayed this year after Chancellor George Osborne announced in his Autumn Statement earlier this month that the increase formula for regulated fares was changing from RPI plus 1 per cent to RPI plus 0 per cent.

Earlier, the Government also announced that the ''flex'' rule, which originally allowed companies to put up some fares by up to 5 per cent above the RPI plus 1 per cent figure, would be limited to 2 pe cent above.

Before these changes, some passengers could have faced season ticket rises of as much as 9 per cent. However, even with the new formula, many passengers will be finding their fare rise far outstripping their wage rise.

Fares on London Underground would have gone up on January 2 as well. But the rise for Tube travellers has been delayed to take into account Mr Osborne's formula-changing ruling.

A Department for Transport spokesman said: ''The Government understands concerns rail passengers have about the costs of fares and the impact they have on household budgets. That is why next year, for the first time in a decade, regulated fares will not rise on average by more than the rate of inflation, offering relief for families and the hard-working people.

''As well as protecting regulated fares, the Government is driving forward the biggest programme of rail modernisation programmes ever, with £38 billion being invested over the next five years.

''That means new state-of-the-art trains, better stations and hundreds of miles of electrified track which will help cut journey times, provide better connections and stimulate growth across the country.''