Britain must partner with EU on defence, says head of Royal Navy helicopter supplier

But Mr Higgins said Britain and Europe needed to work more closely together on defence projects to make the most of tight national budgets, comparing the fragmented way EU states currently buy equipment to the much greater purchasing power of the Pentagon in the US.

That means cooperating on purchases, but also on interoperability — ensuring that new tanks, aircraft and naval vessels use computer systems that can communicate with each other, he explained.

Reaching a broad agreement to work together on defence and security with Brussels is already a stated goal of Sir Keir, with the Prime Minister promoting his proposed pact at a recent NATO meeting as well as a gathering of European leaders at Blenheim Palace.

However, the government is also racing to secure bilateral agreements with key allies, including Germany.

Under former Conservative Prime Minister Boris Johnson, a defence and security pact between the UK and the EU was abandoned.

“I think we’re at the beginning of a different conversation now,” Mr Higgins said. “Clearly, we’ve come out of the EU, out of the Covid pandemic, and we’ve got a new government with a strong majority, who are going to say, ‘OK, what’s right for the UK? And how do we need to have proper conversations about proper things?’

“I see a real opportunity, with the right approach.”

He says Europe is now more aligned, but countries still have “competing national requirements, (so) sometimes you have duplication, tripling and therefore a smaller budget is not spent as effectively on deterrence”.

“Everyone wants to keep jobs, they want to keep technology, they want to keep sovereignty, so there is competition for the euro that will be spent.”

It is right for nations to maintain their own capabilities, says Mr Higgins, but there should be a “more open conversation about where you are going to double or triple” to ensure it makes sense.

His comments will be controversial among some defence experts, who have warned that Britain risks losing its operational independence if it allows itself to be drawn back into the EU grid.

They also take place against an uncertain political backdrop for the Tempest program.

At the Farnborough International Airshow earlier this month, the Prime Minister refused to guarantee the future of the project while the defence review continues, despite insisting it was “important”.

Meanwhile, as Britain and its European allies try to rearm, they are also facing severe budgetary pressures, raising questions about whether the continent can realistically sustain two competing sixth-generation fighter programmes.

The US has spent more than $300bn (£230bn) developing the fifth-generation F-35 jet alone.