Labour leader Sir Keir Starmer may struggle to negotiate a “bespoke” defence and security deal with the EU, a leading think tank has warned.

A major new report by UK in a Changing Europe (UKICE), published today, finds that foreign and security relations between the UK and the EU could improve under a Labour government at Westninster but may fall short of a special new arrangement when it comes to defence industry cooperation.

The response to Russia’s war on Ukraine has shown that global events can increase UK-EU cooperation on foreign policy, its authors said.

And while it pointed out that a potential Donald Trump victory in the US election, “will likely reinforce the sense of the shared challenges faced by the EU and the UK”, such “external drivers” may not be sufficient to propel the EU and the UK towards a truly bespoke security and defence agreement, they added.

The report highlights how Labour and the Conservatives differ in their approach to foreign policy with the EU as an election looms.

It noted that Rishi Sunak's government sees current informal and ad hoc arrangements as the best option for Britain because it allows the government to be “more agile”.

In contrast, the Labour Party aims to “formalise relations”, with the hope of agreeing a “properly bespoke relationship”. 

The report finds that the EU has well-established models for relationships with countries outside the bloc for cooperation on foreign and security policy.

However, none of these, however, seem appropriate for a country with the foreign policy and military heft of the UK, it said.

The in-depth study of UK-EU relations finds that there is scope for a new relationship, but the EU sees the ball as being “in the UK’s court” to push for closer cooperation.

While the EU is likely to welcome further cooperation on foreign policy and crisis management, it is developing a defence industrial strategy focussed on single market members and Ukraine.

A bespoke deal involving UK and EU defence industries therefore “poses significant hurdles”, it warned.

Professor Richard Whitman, Senior Fellow, UKICE said: “Working together closely in supporting Ukraine, the UK and the EU have been reminded that they have a shared view on how to tackle major international challenges.

"However, being like-minded does not automatically translate into effective cooperation - and both the UK and the EU need to be more creative in finding ways to work together for mutual benefit.”

Anand Menon, Director of UKICE, said: "There is - rightly - much talk about shared interests and shared threats. Both the UK and EU will need to think hard about how best to defend the former and react to the other in creative ways in order to ensure that their cooperation is as effective as possible".

Jannike Wachowiak, Researcher at UKICE, added: "The UK does not currently factor in the EU’s thinking around supporting the competitiveness of its defence industry.

"This means a deepening of political contacts may well be the most substantive change under a Labour ‘security pact’. A question for both sides should be whether this is sufficient to respond to today’s security challenges.”

Labour have repeatedly said they want a much closer relationship with the EU, France and Germany on defence, if the party take power after a general election expected later this year.

Shadow Defence Secretary John Healey told POLITICO in December that Labour will upend the Tories’ defence and security policy, by aiming to deepen military cooperation around the EU.

"We would look to put in place systematic cooperation and a defense and security pact with the European Union," Mr Healey said following a visit to NATO headquarters in Brussels in December. "We would begin work directly after the election."