According to the Prime Minister's Office, the UK and Poland are due to sign a new bilateral defence and security treaty in London when Keir Starmer hosts Polish Prime Minister Donald Tusk. The agreement is presented as a response to a more hostile European security environment, bringing defence policy, border security, cyber resilience and action against organised crime into a single framework. The significance lies in the breadth of the package. Downing Street has described it as the biggest step forward in the bilateral defence and security relationship in a generation, and it sits within the government's wider effort to build more structured security ties with European partners after similar agreements with France and Germany.
Downing Street said the leaders will discuss a recent increase in hybrid activity across Europe, including arson, cargo fires, cyber-attacks and espionage linked to hostile actors. The government pointed in particular to Russian-ordered arson in East London and cargo fires in Birmingham and elsewhere in Europe as examples of threats that fall short of open conflict but still carry clear national security consequences. That matters because the current threat picture does not sit neatly inside one department or one institution. A treaty of this kind gives ministers, armed forces, police and security agencies a clearer basis for joint planning, information exchange and coordinated response when pressure is applied through sabotage, digital intrusion or covert interference rather than conventional military attack.
The defence chapter is intended to move beyond routine military cooperation. The Prime Minister's Office said the UK and Poland plan to combine industrial capability and technical expertise in next-generation complex weapons, with an emphasis on maintaining sovereign production chains and supporting high-skilled employment in both countries. One of the clearest measures in the announcement is work on air defence effectors and the co-production of a next-generation medium-range air defence missile. In practical terms, that points to closer procurement planning, common standards and deeper interoperability as both governments place greater weight on air and missile defence.
Land capability forms another prominent part of the agreement. The government said the two countries will expand the use of uncrewed systems and hold large-scale joint exercises focused on counter-drone warfare, electronic warfare and engineering support, with the stated aim of improving readiness on NATO's eastern flank. Poland's position as a frontline NATO state gives that element particular weight. For the UK, the practical benefit lies in training and capability development alongside a partner operating close to the alliance's most exposed border areas. For Poland, the arrangement offers deeper access to British expertise, equipment development and force integration.
The treaty is also meant to tighten cooperation against cyber-attacks and malign information activity. Downing Street said both sides will share expertise, run coordinated exercises and improve how they respond in real time when hostile state actors attempt to disrupt services, steal information or spread disinformation. This is an important policy signal because the announcement treats cyber security, intelligence work and public communications as parts of the same security problem. The operational question now is how quickly departments turn that approach into standing procedures that can be used across government, law enforcement and defence.
Migration and organised crime form a separate operational strand within the package. The UK and Poland are expected to agree a Joint Action Plan on Irregular Migration aimed at disrupting smuggling networks upstream, increasing intelligence sharing and targeting the online methods used by criminal groups to recruit and mislead vulnerable people. The government described Poland as a major migration partner and a frontline state in Europe's migration system. That framing places migration control alongside defence and organised crime in the same bilateral agenda, rather than treating it as a separate policy file. It also points to greater use of joint targeting, surveillance capability and cross-border enforcement coordination.
Politically, the announcement serves a wider purpose in the government's European policy. Downing Street said improved UK-EU relations, with a focus on security and economic opportunity for consumers and businesses, will be high on the agenda of the leaders' talks. The Poland treaty is therefore being presented not only as a bilateral measure, but as part of a broader attempt to deepen practical cooperation with European partners. The next stage is implementation. Defence manufacturers will look for procurement decisions and industrial timelines, while police, border agencies and cyber teams will need clear operating arrangements, data-sharing rules and joint exercises if the treaty is to alter day-to-day capability. The announcement sets the direction; the value of the agreement will be determined by how quickly both governments convert it into operational programmes.