The national rail network operator owes a huge amount of money. In these hard times, new forms of infrastructure funding must surely be found soon

Public transport has its share of galling numbers, usually annual season ticket increases and bonuses for rail industry executives. But the annual figures from Network Rail, which owns and maintains Britain’s rail infrastructure, were particularly arresting.

Even at a time when we are used to blithely discussing enormous sovereign bailouts, Network Rail’s debt of £27bn is daunting. The company’s finance director says it is “below plan and manageable”. These words will sound familiar to anyone with a passing knowledge of macroeconomic events over the past five years. Network Rail’s debt is guaranteed by the government so that it can lean on the state’s so-far AAA rating, while the farepayer’s £6.5bn annual expenditure on the railways is another important contributor. But neither seem a firm foundation, and the same argument applies to Transport for London, owner of the tube network, which owes £6.4bn.

Regardless of the blithe assurances, this mode of funding cannot be transferred to other forms of infrastructure. George Osborne’s vision indicates that, in terms of deficit financing, Network Rail and TfL are the limit. And alarming figures like Network Rail’s will only encourage scrutiny of infrastructure funding models. The chancellor has earmarked £200bn of investment in transport, power and telecoms projects over the next five years and he wants most of the funding to come from the private sector.

If that cannot be found, more radical ideas have to be entertained. This week it was reported that Osborne is considering tapping up savers with the launch of infrastructure bonds.

Ian Mulheirn, director of the Social Market Foundation, argues that benefits for the better off such as free bus passes and winter fuel payments should be cut and reinvested in infrastructure. He says: “We are screaming out for infrastructure investment, but if we are worried about funding it with extra borrowing, then the answer is to cut middle-class benefits that do nothing for growth.”

Roads also have a problem, according to the RAC Foundation, because revenue from motor taxes will fall by £13bn a year by 2029. This is a gap that must be filled by road user charging or toll roads, says the Foundation. Neither the Foundation’s nor the SMF’s ideas are politically palatable. But based on our current economic trajectory and the waning patience of farepayers, the same goes for Network Rail.