The Trident submarine replacement programme will swallow up an extra £400 million of the Ministry of Defence’s budget this year, it was announced yesterday.

The move came only weeks after the cash-strapped department was given a £1 billion funding boost in the budget and has renewed fears about a funding black hole at the MoD.

MPs and industry analysts have acknowledged that investing in the Dreadnought-class submarines now will reduce their cost in the long term, but raised concerns about how other major equipment projects will be funded. They warned that the MoD will need significantly more cash in the government’s Whitehall-wide spending review next year in order to avoid deep cuts across the rest of the department.

The National Audit Office warned last month