The massive programme to build replacement nuclear submarines for the Royal Navy “cannot and must not slip” the Defence Secretary warned as he pushed the button to start work on the massive £41bn project.

Michael Fallon, speaking as he started the machine to cut the first steel for the 17,000-tonne “Successor” class of nuclear missile submarines at BAE Systems’ plant in Barrow-in-Furness, said he was “throwing down the gauntlet” to industry.

“Successor can’t be late because the Vanguard submarines [the current generation of Trident submarines] are coming to the end of their working life,” Mr Fallon said.

“We will absolutely challenge BAE and other suppliers such as Rolls-Royce. They are going to be incentivised to keep the targets and they will suffer if they don’t.”

Speaking in the BAE plant’s huge Devonshire Dock Hall with the two of the troubled Astute-class attack submarines behind him, Mr Fallon said the country could not afford the delays or cost overruns previous submarines had suffered, as its security depended on the replacement Trident submarines.

The first of the Astute class attack submarines was four years late and the project was £2bn over budget. Troubles included issues with the nuclear reactor provided by Rolls and concerns about the quality of work and equipment overseen by BAE.