In an attempt to signal that the UK’s close friendship with Poland will continue after Brexit, the Prime Minister is to announce a string of military initiatives including join training, exercises and information sharing.
She will also back close co-operation to help tackle cyber threats and alleged Russian “fake news” propaganda.
Britain will provide £5million for a new joint strategic communications project that will include measures to detect and counter Russian information operations.
Speaking ahead of her visit, the Prime Minister said: “Poland matters greatly to the UK – our partnership is broad, vibrant and diverse and we both share a steadfast commitment to Europe’s security and defence.
“I am determined that Brexit will not weaken our relationship with Poland. Rather, it will serve as a catalyst to strengthen it.
“And that is why I am in Warsaw today, to ensure that we can work even more closely together to ensure the security and prosperity of our nations in the years ahead.
“Although the UK is leaving the European Union, we are not leaving Europe.
“And I will reaffirm to Prime Minister Morawiecki that we want to work with Poland and the other member states in the future to protect our shared values, people and interests.
“We are building a strategic partnership from a base of shared history and deep ties of friendship that will continue to flourish long after our departure from the EU.
“The bilateral defence treaty we are signing today is a powerful symbol of our continued close cooperation.”
Mrs May will be joined by senior ministers including Chancellor Philip Hammond, Foreign Secretary Boris Johnson, Home Secretary Amber Rudd and Defence Secretary Gavin Williamson at the annual British-Polish summit.
The Prime Minister could face some difficult diplomacy in Warsaw after a furious row over democratic rights erupted between the Polish government and the EU earlier this week.
The European Commission yesterday threatened to strip Poland of EU voting rights following controversial judicial reforms being introduced by Poland’s hard-line conservative government.