Potocki attempted to offer another deal to Prussia, namely, to support Prince Louis Charles of Prussia for the Polish throne, but Frederick William II of Prussia, advised by Ewald Friedrich von Hertzberg, refused that offer, as it did not seem profitable enough to Prussia, which was interested more in territorial gains than in a potentially-strengthened Commonwealth, which could ask for the return of the territories lost in the First Partition. The passing of the Constitution of 3 May 1791, although officially applauded by Frederick Wilhelm II, who sent a congratulatory note to Warsaw, caused further worry in Prussia. The Prussian statesman Ewald von Hertzberg expressed the fears of European conservatives: "The Poles have given the coup de grâce to the Prussian monarchy by voting a constitution", elaborating that a strong Commonwealth would likely demand the return of the lands that Prussia acquired in the First Partition. Finally, Prussian-Russian relations stabilised with the end of the Triple Alliance, which was cemented by the British-Netherlands-Prussian-Russian treaty of 26 July 1791 in which the Triple Alliance de facto capitulated to all Russian demands. In the meantime, similar negotiations of a never-realised Polish–Swedish alliance fell through as well.
