GAVIN Williamson, the Tory Defence Secretary who has aspirations to replace Theresa May as prime minister, revealed yesterday that Britain’s seventh Astute-class nuclear submarine is to be named Agincourt.

Although it will not be the first Royal Navy vessel to be named after Henry V’s famous victory against France in 1415, a story immortalised by Shakespeare, the choice did raise a few eyebrows in Westminster.

The SNP defence spokesman, Stewart McDonald, was a little surprised by the decision. He pointed out that Scotland wasn’t involved in the battle, where a much larger French army was defeated by smaller, English and Welsh forces.

The MP tweeted: “New nuclear submarine announced by the MoD today to be named ‘Agincourt’, after the famous English battle against the French in 1415.

“As Scotland’s sympathies lay elsewhere then and that the battle pre-dates the Union, can we assume we’re not contributing to the £2.5bn cost?”

The Labour Party whip’s office tweeted: “Govt announce that Astute Boat will be called Agincourt, sure that will go down well with the French...”

Williamson was at BAE systems base in Barrow in Furness yesterday to reveal the name, and confirm that the Government will meet the £1.5 billion cost of the submarine.

He also confirmed another £960m would go towards the Dreadnought programme, which involves four new submarines to carry the UK’s Trident nuclear deterrent.

Williamson promised the work would secure at least 8000 jobs.

He said the new submarine was essential to keep the UK safe “from intensifying threats”.

He added: “Agincourt will complete the Royal Navy’s seven-strong fleet of hunter-killer attack subs, the most powerful to ever enter British service, while our nuclear deterrent is the ultimate defence against the most extreme dangers we could possibly face.”

Plans for the seventh and final Astute-class ship were first announced in the Strategic Defence and Security Review in October 2010.

With the Ministry of Defence facing a budget shortfall of up to £20.8bn over the next decade, it looked as if work on the submarine might not get under way.

The tussle over the cost was only resolved after a very public clash between Williamson and Chancellor Philip Hammond that resulted in the Treasury being forced into signing off the money needed.

But there still were questions, too, over what was being scrapped to afford the new spending commitments made by Williamson.

“What this announcement does not address is whether savings will have to made elsewhere in the defence budget in order to reflect the high priority being given to submarine procurement, and indeed the Royal Navy as a whole,” said Malcolm Chalmers, deputy director-general at the Royal United Services Institute think tank.

SNP MSP Bill Kidd said the Government had the wrong priorities. He said: “Rather than spending hundreds of billions on nuclear weapons, the Tories should be investing in our conventional defence forces and public services.

“The Tories simply cannot be trusted to deliver for our armed forces, as the totally unjustified, immoral and escalating cost of their nuclear obsession comes at the expense of our defence bases, troop numbers, and equipment.

“The country’s military capability must not be undermined by an incompetent Tory Government’s bad budgeting, bad planning and lack of a coherent long-term strategy for the country’s defence estate.”

Last week, Westminster’s Public Accounts Committee warned that defence chiefs had lost control of their budget.

The committee report said the Ministry of Defence, “simply does not have enough money to buy all the equipment it says it needs”.

MPs were sceptical that a current defence review, due to conclude in July, would fix a funding gap of between £4bn and £21bn.