More than 100,000 people gathered in Budapest for a concert urging citizens to vote out Prime Minister Viktor Orban on Friday. 

Over 50 bands, all performers who have used their music to express dissent against Mr Orban's nationalist-populist government, played one song each during the seven-hour, 'system-breaking' concert.

The crowd, largely made up of young people, frequently broke into anti-government chants, including 'Ruszkik haza!' or 'Russians go home!'

It was a refrain from Hungary's 1956 anti-Soviet revolution that has taken on renewed significance as Mr Orban has forged increasingly close relations with Moscow.

The concert came just two days before Hungary's elections, with Orban trailing in the polls despite a glowing endorsement from US Vice President JD Vance. 

The Hungarian PM, a right-wing nationalist who has ruled for 16 years, is supported by just 30 per cent of voters compared to 39 per cent backing his rival Peter Magyar, according to a poll released on Thursday.

His falling popularity has prompted a major intervention from Vance, who travelled to Budapest on Tuesday in a last-ditch attempt to boost his support.

Standing alongside Orban, the US Vice President said he was in the Hungarian capital 'to help him in this campaign cycle'.

Vance and his wife were welcomed to Budapest by Foreign Minister Péter Szijjártó, who said Orban's warm friendship with Donald Trump had created a 'new golden age' in relations.

The vice president launched a scathing attack on the EU and Ukraine, accusing the EU of attempting to rig the election against Orban.

He said the EU had presided over 'one of the worst examples of foreign election interference that I have ever seen or ever even read about... because they hate this guy'.

He also said 'part of the reason' for his visit was because 'interference that's come from the bureaucracy in Brussels has been truly disgraceful'.

One attendee at Friday's concert, Helena Sugar, 19, said she was drawn to the event by some of her favourite artists, but that the desire for change was the concert's most crucial aim.

'I listen to these performers every day. But now the most important thing here is the political goal,' she said.

'I think it is important to show how many of us think this way, how many of us think that the time for this system is over, and it is time for us to change.'

The group organising the event, the Civic Resistance Movement, wrote that each song to be performed was 'critical of the corrupt regime', and meant to 'demonstrate to the masses of voters and make them realise that the era of impunity is over'.

The big turnout in Budapest's Heroes' Square and the concert's anti-government atmosphere reflected the broad level of dissatisfaction with Mr Orban's government, especially among Hungary's youth.

In addition to the throngs of people in the streets, more than 100,000 were following a livestream online.

A generational gap has been widening in Hungary, with its young people pushing overwhelmingly for an end to Mr Orban's autocratic rule, while the oldest citizens remain loyal to the prime minister.

Mr Orban and his Fidesz party's declining popularity comes amid economic stagnation, political and corruption scandals and the rise of a new opposition challenger that is posing the biggest threat to the prime minister's power in nearly two decades.

That challenger, the centre-right Tisza party and its leader Peter Magyar, have galvanised large numbers of voters across Hungary who see him as the most credible challenger yet to Mr Orban's 16-year grip on power.

A recent survey by pollster 21 Research Centre found that 65 per cent of voters under 30 support Tisza, while only 14 per cent back Mr Orban.

One concertgoer, 22-year-old Noel Ivan, said he had immigrated from Hungary to Austria seeking a better life, but that he 'would like to move back and plan the future at home, which is currently hopeless and deeply sad'.

He added that although he does not consider himself conservative, he wants to 'contribute to regime change by voting for the Tisza party'.

Friday's performers included some of Hungary's most popular acts: singer Azahriah, rappers Beton.Hofi and Krubi, and alternative rock bands Quimby and Ivan and the Parasol.

Another performer, Benedek Szabo, the frontman and lead songwriter for the popular band Galaxisok, told The Associated Press that for him, Hungary's increasingly close connections with Moscow were tantamount to 'selling out the EU allies to Russia'.

'Everyone's fed up, and everyone's ready to finally change this system, to finally send a message,' he said.

'Not only today, but the day after tomorrow, that we've had enough, and we want to belong to Europe.'

Galaxisok performed a song that laments what the band sees as missed opportunities and wasted years under Mr Orban's rule.