Sir Keir Starmer wants Britain treated as if it was an EU member state in the bloc’s €800 billion plan to rearm Europe.

London is pushing for UK defence companies to be classified as “European” in the project but faces opposition from Paris, which wants preferential treatment reserved for EU members only.

Brussels is finalising the £652 billion plan to dramatically raise defence spending and manufacturing to deter Russian aggression by arming the continent and Ukraine.

The scheme includes a “buy European” clause to boost domestic suppliers and reduce reliance on the United States but it is not decided if the UK will be included.

France is against British defence companies joining the mission on the same terms as other European manufacturers, because the UK is not part of the EU. This comes despite Emmanuel Macron and Sir Keir working “hand in glove” on the European response to Donald Trump’s peace negotiations with Vladimir Putin.

Ursula von der Leyen, the European Commission president, the Netherlands, Poland and the Baltics, have signalled support for treating UK defence companies as “European”.

“While Macron is playing nice with Starmer in front of the cameras, he’s actively working to shut the UK out of the EU’s defence spending plans,” an EU diplomat said.

A Government spokesman said: “We live in challenging times – global geopolitical instability and war in Europe means enhancing our defence capability is important.

“This includes closer cooperation with the EU, with Nato remaining the cornerstone of our security.”

Asked about UK involvement in “buy European”, the spokesman said: “We welcome efforts to enhance the EU’s defence production.

“European allies need to step up across the board and we need a new approach that brings European efforts together and galvanises further action.”

The UK defence industry was worth about £38.2 billion to the economy in 2023, directly employs about 142,000 people and supports a further 110,000 indirect jobs.

The Government is looking to revamp the industry, reach a new defence spending target of 2.5 per cent of GDP by 2027, while stimulating economic growth.

The EU gets about 80 per cent of its defence equipment from non-EU suppliers, with a large amount coming from the US.