The leaders met to formalise a treaty intended to protect British borders, tackle organised crime, and bolster collective defences.
Sir Keir Starmer hailed a “generational uplift” in the UK’s defence and security ties to Poland, as he signed a new treaty with Donald Tusk.
The Prime Minister held talks with his Polish counterpart at RAF Northolt in west London on Wednesday, before they visited the nearby Battle of Britain Bunker museum, where they laid a commemorative wreath.
The leaders met to formalise a treaty intended to protect British borders, tackle organised crime, and bolster collective defences, while deepening co-operation with the European Union.
It comes as both countries face increasing threats, particularly from Russia, with the UK having signed similar treaties with France and Germany.
Speaking alongside Mr Tusk, Sir Keir said the historic relationship between the two countries was “reinforced as we face the challenges of today”.
He said: “There’s no greater challenge for either of our countries than the challenge of Russian aggression, and we see that not just in Ukraine itself, but beyond Ukraine, impacting on our own countries.
“So that’s the context in which we sign what is actually a generational uplift in the relationship on security and defence between our two countries.”
Speaking through an interpreter, Mr Tusk said he wanted to thank Sir Keir for his commitment to defending “our shared values”.
He said: “You and I are both subscribers to those values.
“Some people might say these values are now old-fashioned and obsolete, but they are important for us and for our nations – rule of law, democracy, human rights, the sense of solidarity with others and the intention to protect their security and their welfare. That is the foundation of the treaty.”
The Government hopes the agreement will unlock major defence benefits by allowing both forces to combine expertise and industrial capability.
This will include new air defence technology, including the co-production of next‑generation medium‑range air defence missile.
The UK and Poland will also step up the use of uncrewed systems to reinforce Nato’s Eastern Flank, with large-scale joint exercises planned.
During the visit, Sir Keir also spoke to servicemen and women with links to Poland.
He praised the Polish pilots who fought with the UK during the Second World War and said the families of many of them who remained in the area were “still a living part of our community”.
