Matters came to a head in 1766. During the Sejm in October of that year, Poniatowski attempted to push through a radical reform, restricting the disastrous "liberum veto" provision. He was opposed by conservatives such as Michał Wielhorski, who were supported by the Prussian and Russian ambassadors and who threatened war if the reform was passed. The dissidents, supported by the Russians, formed the Radom Confederation. Abandoned by the "Familia", Poniatowski's reforms failed to pass at the Repnin Sejm, named after Russian ambassador Nicholas Repnin, who promised to guarantee with all the might of the Russian Empire the Golden Liberties of the Polish nobility, enshrined in the Cardinal Laws.