The UK and Germany will face threats together, Prime Minister Andy Burnham has said as he reaffirmed a series of defence and security partnerships.

On his first official European trip outside of Ukraine, Burnham was greeted with military honours in Berlin on Thursday and met German Chancellor Friedrich Merz.

Speaking to reporters at the German capital’s Federal Chancellery, the PM said both countries were facing hybrid attacks “on a regular basis” and “it makes sense” to take them on together.

The pair formally ratified the 2025 Kensington Treaty, a partnership committing both countries to tackle hostile activity.

Burnham said the treaty would “improve our security here in Europe” but also help grow the economy and living standards.

He added that the UK government would now “seek to progress” Germany joining Gcap, the Global Combat Air Programme led by Italy, Japan and the UK to develop a next-generation fighter aircraft.

He also announced partnerships on quantum technology and space – and said he was aiming to host a joint meeting of the UK and German cabinets next year.

The Berlin talks come after intelligence services warned of rising threats, including last month when Germany accused Russia of launching a drone fitted with explosives at Leipzig/Halle Airport.

Meanwhile, French finance minister Roland Lescure has invited Britain to “come all the way” back to the European Union, in an interview with the BBC’s economics editor Faisal Islam.

Ahead of a UK-EU summit next month, Burnham said he was “very committed to securing deeper cooperation” and to “see if we can bring the UK closer to Europe”.

He told reporters a closer relationship with Europe was in the interests of growth and tackling irregular migration.

In recent weeks he has mentioned the prospect of eventually rejoining the bloc.

A German government spokesman has said any future in-out referendum would be primarily a question for Britain, but that Berlin supports stronger ties between the UK and the EU.

Speaking ahead of the visit, Burnham said the UK and Germany were “joining forces to find, expose and disrupt” threats.

European leaders have warned the threat of hybrid attacks against Europe by Russia has intensified in recent weeks.

Hybrid attacks can include potentially destabilising activity such as cyber attacks, sabotage or misinformation.

Sir Mark Lyall Grant, former UK national security adviser, explained that hybrid warfare “falls somewhere between peace and war – it’s in that sort of grey zone, an area where Russia has been extremely active for some time”.

He told Radio 4’s Today that while Russia had posed a threat to the UK since Vladimir Putin became president in 2001, there had been an “intensification” in response to European support for Ukraine following Russia’s invasion.

“We know Russia has been mapping undersea cables in the North Sea; that’s something I’m sure Andy Burnham will be talking to Chancellor Merz about because it affects both the UK and Germany,” he added.

Last month, a senior Russian diplomat was summoned by the British government over an “egregious and reckless attack” on Leipzig airport, while the EU’s foreign affairs chief also summoned Russia’s envoy in Brussels.

It is a major international freight hub used for providing support to Ukraine. Moscow has denied any involvement in the incident.

Meanwhile, questions have been raised this week about Germany’s reliability as an intelligence partner, following the bombshell arrest of a former spy chief on suspicion of espionage.

The talks also come during a period in which Merz’s own political future has come under intense scrutiny.

Burnham replaced Prime Minister Sir Keir Starmer in July after the former leader was forced out by his own MPs just two years after winning a landslide election victory.

Similarly, Merz has faced persistent rumours he could be replaced by his party due to his poor approval ratings and following setbacks in regional elections.

Although the chancellor appears to have overcome an immediate crisis in his leadership, questions remain over his future.

Additional reporting by Ottilie Mitchell.

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