Thousands of protesters have demanded the ouster of Hungarian Prime Minister Viktor Orban, criticising the leader's moves to forge closer ties with Russia at a time of an escalating conflict in Ukraine.

The rally in Budapest on Sunday came a day before a visit by German Chancellor Angela Merkel, who was due to meet with Orban.

Balazs Gulyas, an organiser of the "Spring Comes, Orban Goes" rally, said the demonstration was an attempt to tell the European Union that the majority of Hungarians did not agree with Orban's foreign policy.

"We want to show that the country is not equal to Orban, that the majority does not support his policies going closer to Vladimir Putin," said Gulyas. "The majority of the people want to be in the EU."

Protesters held up signs and chanted slogans to demand that Hungary stay within the EU's fold and away from the Kremlin's orbit, demanding Orban's ouster for eroding democratic freedoms, perceived corruption and diplomatic conflicts with the West.

"We dislike the directed democracy, the kind of dictatorship Putin has built in Russia. And this is the direction in which the Orban government is going," protester Jozsef Bruck told the Reuters news agency.

Nuclear reactors

Orban's dealings with Moscow, including an agreement for Russia to build new reactors at Hungary's nuclear power plant and a loan of $11.3bn to help finance the project, are expected to be on the agenda for the meeting between the Hungarian and German leaders.

Orban's Fidesz party has seen a steep fall in popularity in recent months, highlighting cracks within the party whose core members have begun to grow restive.

Helped by a weak opposition, Orban remains firmly in control of Hungary and of the party he has led for most of its 27-year history. He does not face another parliamentary election until 2018.

Source: Agencies