Tens of thousands of Hungarians rallied in Budapest on Saturday to commemorate a 1956 anti-Soviet uprising and show support for nationalist Prime Minister Viktor Orban, who faces a tight election race next year.

For the first time since he came to power in 2010, Orban, 58, will face a united front of opposition parties including the Socialists, liberals, and the formerly far-right Jobbik, now rebranded as center-right, in 2022 parliamentary elections.

The alliance, is led by Peter Marki-Zay, a 49-year-old Catholic conservative father of seven and small-town mayor who seems to embody the traditional values Orban publicly champions. It's seen as a formidable challenger.

Marki-Zay was due to mark his first appearance as an official prime ministerial candidate at a separate rally organized by the opposition in the capital on Saturday.

Organizers of the pro-government rally, marching across the Danube river to central Budapest where Orban was due to give a speech, say they want to send a message of unity to the opposition and Brussels.

The anniversary of the 1956 uprising gives Orban a symbolic platform for his agenda as his Fidesz party scales up its pre-election campaign. He has showered the electorate with handouts, including a $2 billion income-tax rebate for families, and stepped up his strong anti-immigration rhetoric.

While stating that Hungary's interest is to remain a member of a strong European Union, Orban has clashed with Brussels over his policies, including tighter media freedoms and opposing ceding more powers to the EU.