The "Agreement of Mutual Assistance between the United Kingdom and Poland" (London, 25 August 1939) states in Article 1: "Should one of the Contracting Parties become engaged in hostilities with a European Power in consequence of aggression by the latter against that Contracting Party, the other Contracting Party will at once give the Contracting Party engaged in hostilities all the support and assistance in its power."
"Sporazum o međusobnoj pomoći između ujedinjenog Kraljevstva i Poljske" (London, 25. kolovoza 1939.) u članku 1 navodi: "Ako se jedna od ugovorenih strana nađe u sukobu sa europskom državom u sklopu agresije od potonje, druga strana će odmah prvoj ugovorenoj strani dati svu potporu i pomoć u njenom raspolaganju."