Tens of thousands of demonstrators of various political stripes are expected to take to central streets Thursday for rallies and protests on the May Day holiday.

The Communists are expecting 50,000 demonstrators to gather at Kaluzhskaya Ploshchad at 10 a.m. Thursday and march to Teatralnaya Ploshchad, where Communist Party leader Gennady Zyuganov will address the crowd, a party spokeswoman said Monday.

The demonstration will likely feature anti-government sentiment. Several hundred activists from left-wing youth groups are expected to participate in the march, including Red Youth Vanguard, whose web site promises a "Day of Anger" with the slogan "Down With Succession to the Throne!"

President-elect Dmitry Medvedev, President Vladimir Putin's handpicked successor, is to take office May 7.

A less confrontational rally will join together almost 30,000 activists from the pro-Kremlin party United Russia and the pro-government Federation of Independent Trade Unions, spokespeople for both organizations said.

The demonstrators will gather at Belorussky Station at 9 a.m. and march down 1st Tverskaya-Yamskaya and Tverskaya Ulitsa to the Mayor's Office, said Natalya Burtseva, a spokeswoman for United Russia's Moscow branch.

Between 3,000 and 4,000 United Russia activists will march, Burtseva said. Around 25,000 trade unionists will participate, Mikhail Shmakov, a spokesman for the trade union federation, told Interfax.

Children will also participate in the march, which will feature banners with slogans such as, "United Russia: Together We Will Win," Burtseva said.

Following the April 14, 2007, Dissenters' March in Moscow, in which opposition activists were violently dispersed by riot police, United Russia leader and State Duma Speaker Boris Gryzlov said public gatherings should be "festive in nature" and that people should "take to the street and celebrate certain events."

May 1, called the Day of Workers' Solidarity in Soviet times, was once celebrated with mass processions through Red Square, where thousands of people marched, waving flags and holding portraits of Soviet leaders. Late President Boris Yeltsin renamed the holiday the Day of Spring and Labor in 1996.

Activists from the ultranationalist Movement Against Illegal Immigration will gather at 12 p.m. Thursday near the entrance of the All-Russia Exhibition Center, the organization said on its web site. Demonstrators will chant, "Higher Wages!" and "Down With Immigration," it said.

The liberal Yabloko party is planning a "Citizens' March for Freedom and Justice" starting at 11:30 a.m near the Solovki memorial on Lubyanskaya Ploshchad, where the former KGB headquarters are located. Demonstrators will march to Slavyanskaya Ploshchad, where several speakers will address the crowd, the party said.

The May holidays traditionally are the start of the dacha season, when tens of thousands of city dwellers head for their plots of land in the countryside.

Because the May 1 holiday falls on a Thursday, the government has made Friday and Saturday holidays this year to give the country a three-day weekend. Sunday is an official working day.