Network Rail’s debts have soared to more than £41.6bn, following a “tough” 12 months.
Debts at the organisation rose by 10 per cent to £41.6bn for 2015/16, up from £37.8bn in 2014/15.
Borrowing is also expected to rise “significantly” over the coming years, with debts expected to hit £52bn by March 2019.
The figures were revealed as part of Network Rail’s annual report, in which chief executive Mark Carne admitted it had been a “tough year” for the organisation.
Pre-tax profit dropped by 18.8 per cent to £411m, from £506m the year before.
The rail body was £210m over budget in delivering enhancements, with much of this down to delays on the Great Western Main Line improvement programme.
Network Rail’s net financial performance was £149m lower than expected, due to higher renewal costs across signalling, track and civils projects.
The Office of Road and Rail criticised Network Rail’s performance in delivering enhancement and renewals, saying work had “cost more than expected with network performance not improving”.
It added that cost overruns were putting pressure on Network Rail’s ability to borrow from the government, meaning less money could be invested back into the railway.
ORR chief executive Joanna Whittington said she wanted to see “noticeable improvements in performance” and “greater financial efficiency” over the next 12 months.
For the first time in its history, Network Rail suffered no workforce fatalities for the year 2015/16.
The number of lost-time injuries stood at 684, up from last year’s 674 figure, but Network Rail was commended for its improved safety performance by the ORR.
Nevertheless, the watchdog said there was room for improvement and highlighted some “underlying [health and safety] issues”, such as safety rules and procedures not being followed consistently on certain sites.
Network Rail delivered a record amount of enhancements across the network in 2015/16, with more than £3.5bn spent improving the network, compared with £3.4bn the year before.
More than 80 per cent of enhancement and renewal milestones were hit, while nine out of 10 of Network Rail’s biggest infrastructure renewals and enhancement milestones were met.
Mr Carne said: “It has been a tough year for the rail industry – the year of reviews – but we can also look back at the last 12 months and take pride in many achievements.
“We have carried more passengers than ever before, we have increased the reliability of our infrastructure assets, we have successfully delivered our biggest ever programme of bank holiday works and we are investing £100m every single week on improvements for passengers as part of our Railway Upgrade Plan.”