Hungary’s longtime Prime Minister Viktor Orban has conceded defeat in the country’s parliamentary election after partial official results showed Peter Magyar’s Tisza party winning by a landslide.

“Prime Minister Viktor Orban just called to congratulate us on our victory,” Magyar posted on social media on Sunday as the results rolled in.

With 97.35 percent of precincts counted, Magyar’s centre-right party secured 138 seats in the 199-seat parliament on 53.6 percent of the vote, while nationalist Orban’s Fidesz took just 55 seats with 37.8 percent, according to official results.

In a victory speech to tens of thousands of supporters gathered along the Danube River in the capital, Budapest, Magyar said his voters had rewritten history.

“Tonight, truth prevailed over lies,” he said. “Today, we won because Hungarians didn’t ask what their homeland could do for them; they asked what they could do for their homeland. You found the answer. And you followed through.”

Magyar said the results – projecting his party winning a two-thirds majority in parliament – represented a historic mandate and pledged to unite all Hungarians. “In the ⁠history of democratic Hungary, this ⁠many people ⁠have never voted before, and no single party has ‌ever received such a strong mandate ‌as ‌Tisza.”

Reporting from the victory party, Al Jazeera’s Step Vaessen described scenes of jubilation.

“Budapest has absolutely exploded into celebrations,” she said. “It’s all over for Viktor Orban after 16 years. They can barely believe it, but it’s absolutely happening.”

One voter, Daniel Hernandez-Kontler, said he expected Magyar to “build bridges” rather than “divide Hungary”. Speaking to Al Jazeera, he said he expected “a more human Hungary that is for everyone, not just the Fidesz sympathisers.”

For his part, Orban told his followers that he had “congratulated the victorious party” after a “painful” but “clear” result.

“The ⁠responsibility and possibility ⁠of governing was not given to us,” he said. “We are going to serve the Hungarian nation and our homeland from opposition as well.”

Al Jazeera’s Vaessen said that “the comfortable two-thirds majority” that Magyar’s party was projected to win was “very important”, as it would allow it to amend Hungary’s constitution.

“It is a big change for Hungary because for the past 16 years, Fidesz has had a comfortable majority in parliament and Orban could govern as he pleased,” Gergeley Rejnai, a Hungarian analyst at the Centre for Fair Political Analysis, told Al Jazeera.

“Now, it’s going to be completely flipped,” he said.

‘In the mainstream of the EU’

The National Election Office said the turnout by 6:30pm (16:30 GMT) was more than 77 percent, a record number in any election in Hungary’s post-Communist history.

Orban’s defeat will have significant implications not only for Hungary, but for the European Union, Ukraine and beyond.

It will likely spell an end to Hungary’s adversarial role inside the EU, possibly opening the way for a 90 billion euro ($105bn) loan to war-battered Ukraine, which had been blocked by Orban.

Rejnai said Hungary is expected to align more closely with Western European allies, putting itself “in the mainstream of the European Union”.

Defeat for Orban could also mean the eventual release of EU funds to Hungary that the bloc had suspended due to what Brussels said was Orban’s erosion of democratic standards.

Orban’s exit would also deprive Russian President Vladimir Putin of his main ally in the EU and send shockwaves through Western right-wing circles, including US President Donald Trump’s MAGA followers.

US Vice President JD Vance had visited Hungary earlier this week to rally with Orban, attacking the alleged interference in Hungary of Brussels “bureaucrats”, while Trump had promised to bring US “economic might” to Hungary if Orban’s party secured victory.

In Hungary, a Tisza victory could open the way for reforms that the party says would aim to combat corruption and restore the independence of the judiciary and other institutions.

However, the extent of such reforms will depend on whether Tisza secures the two-thirds constitutional majority it would need to reverse much of Orban’s legacy.

Orban sought to cast Sunday’s election as a choice between “war and peace”. During campaigning, the government blanketed the country with signs warning that Magyar would drag Hungary into Russia’s war in Ukraine – something he strongly denies.