Rail fare increase may be final straw for Tory commuters in key marginals - Telegraph.co.uk

But ministers might want to tell passengers why fares are continuing to spike when Network Rail has already slashed its running costs over the past five years.

According to Sir David Higgins, the company's chief executive, the Treasury will have already netted a rebate of £310 million by April 2014 thanks to efficiency improvements already in place.

On coming to office, much to many observers' surprise, the Coalition did not take an axe to investment plans already in place.

But such generosity came at a price and within months they reversed two key decisions by the previous Government.

One was to scrap the one per cent above inflation limit on fare rises, which had been in place for years.

The other was to reintroduce a system known as "Flex", allowing train operators to push some fares up by eye-watering amounts.

Lord Adonis, the Transport Secretary in the last Labour Government, regarded Flex as political suicide. He did not want to be the politician telling the good folk of Canterbury - a station which seems to be regularly stuffed by the system - why their fares were going up by more than 10 per cent.

There is one glimmer of hope for commuters. Last year Justine Greening, the current incumbent, persuaded the Treasury to cough up the cash to bring the increase in the cost of season tickets down to an average of one per cent above inflation.

Network Rail's improved efficiency should enable her to make the case again which, given the number of marginal seats on key commuter routes, may make good political sense.