A SPENDING watchdog has found a £2.9 billion black hole in the Ministry of Defence’s programme to maintain and renew Trident.

The National Audit Office (NAO) warned the shortfall could “destabilise” the MoD’s entire equipment plan because the spend on designing, producing and maintaining the Clyde-based submarines which carry the Trident missiles and their nuclear warheads accounts for one-quarter of the total.

The MoD intends to plough £50.9bn into Trident programmes over the next 10 years. It has already had to find to £3bn in efficiency savings in order make affordable the £31bn Trident renewal programme, which will replace the ageing Vanguard-class submarines with four new Dreadnought-class boats. Defence chiefs have also had to gain the Treasury’s permission to draw £600 million from a £10bn contingency fund for the programme and to delay work on a replacement for the Astute-class attack submarines by two years.

The NAO said the MoD may have to take more from the contingency fund if it is to cover the extra £2.9bn which it needs to find by 2028.

“Problems with the affordability of the enterprise action plan could destabilise the department’s overall equipment plan given that around a quarter of its planned spend on equipment relates to nuclear programmes,” the NAO said.

In this financial year alone, the MoD is forecast to spend £5.2bn across the nuclear enterprise, accounting for 14% of the MoD’s total budget. That includes £1.8bn on procuring and supporting submarines, £1.4bn on missiles and warheads, £790m on propulsion systems and £220m on managing the enterprise.

The NAO said the MoD has introduced new ways of working with its main contractors on the Dreadnought programme, BAE Systems and Rolls-Royce. However, it now faces skills shortages, lacking 337 skilled personnel across seven military nuclear specialisms.

NAO boss Sir Amyas Morse said: “The coming years are crucial. The department needs to ensure the new structures, processes and workforce operate effectively to manage the £2.9bn affordability gap.”

An MoD spokesman said: “Dreadnought is one of the most complex engineering programmes ever undertaken by the UK. The report highlights our position that it is on track to be delivered on schedule and within the original estimated cost.”