DEFENCE bosses have ordered a review into the Barrow-built Dreadnought submarine programme amid concern over delays, according to a national newspaper.

A report in the Sunday Times claimed that the Ministry of Defence had commissioned a review into the £41 billion project to replace the country's Trident submarines.

Staff at the BAE shipyard are working on four new nuclear warhead-armed boats which are said to be due to enter service in the early 2030s.

They will replace the ageing Vanguard submarine, which have continued to be used later than planned.

It comes amid concern the programme is behind schedule and potentially over budget, although the MoD and BAE have repeatedly denied such delays.

The arrival of the first Dreadnought-class boat has been pushed back from 2024 and the budget has swollen to £31 billion, plus £10 billion of contingency cash.

The boats make up the Continuous At Sea Deterrent, in which one submarine is active at all times.

Delays to seven Astute hunter-killer submarines have also eaten into its schedule, and there have been problems with vital new infrastructure, the newspaper reported.

The MoD has so far not disclosed construction milestones for Dreadnought.

An MoD spokesman said: “We regularly review all our equipment programmes, including the delivery of our Dreadnought-class submarines. The programme remains on track to deliver to schedule, with the first in class expected to enter service in the early 2030s.”

BAE said: “We are committed to delivering to schedule the submarines for the Royal Navy.

Some 30,000 people employed in the programme and supply chain.