May Day was celebrated illegally in Russia until...

May Day was celebrated illegally in Russia until the February Revolution enabled the first legal celebration in 1917. The following year, after the Bolshevik seizure of power, the May Day celebrations were boycotted by Mensheviks, Left Socialist-Revolutionaries and anarchists. It became an important official holiday of the Soviet Union, celebrated with an elaborate popular parade in the center of the major cities. The biggest celebration was traditionally organized in Red Square, where the General Secretary of the CPSU and other party and government leaders stood atop Lenin's Mausoleum and waved to the crowds. In 1991, which preceded the last year that demonstrations were held in Red Square, May Day grew into high-spirited political action. Around 50,000 people participated in a rally in Red Square in 1991 after which the tradition was interrupted for 13 years. In the early post-Soviet period the holiday turned into massive political gatherings of supporters of radically minded politicians. For instance, an action dubbed as "a rally of communist-oriented organizations" was held in Red Square in 1992. The rally began with the performance of the Soviet Union anthem and raising the Red Flag and ended with appeals from the leader of opposition movement Working Moscow, Viktor Anpilov, "for early dismissal of President Boris Yeltsin, ousting Moscow Mayor Gavriil Popov from power and putting the latter on trial". Since 1992, May Day is officially called "The Day of Spring and Labour", and remains a major holiday in present-day Russia. (wiki with my own corrections)
https://youtu.be/F31YwZZGlW4