BUDAPEST, Hungary — Hungary’s election winner Péter Magyar called Monday on the country’s president to convene the parliament to form a new government “as quickly as possible,” in hopes that he can take over from Viktor Orbán as prime minister as early as May 5.

Speaking at a news conference after his Tisza party’s victory Sunday, Magyar said they received “a never-before-seen mandate.” That super-majority would allow Tisza to embark on ambitious program and reforms.

“The Hungarian people didn’t vote for a simple change of government, but for a complete change in regime,” he said.

Magyar thanked Moscow and Beijing for offering their congratulations and willingness to work with Hungary’s new government.

“Hungarians said yesterday they will write their history, not in Moscow, not in Beijing, not in Washington,” he added.

In his campaign, Magyar pledged to end Hungary’s drift toward Russia and restore its ties with European allies. He promised voters that after 16 years of autocratic governance and the erosion of the rule of law under Orbán, he will root out corruption and create a “peaceful, functioning and humane” Hungary.

But what those changes will look like remains to be seen. During his long time in office, Orbán ruled with the power of a two-thirds parliamentary majority, allowing him to pass a new constitution, rewrite the electoral system and reshape the judiciary.

Magyar’s Tisza party secured exactly such a mandate Sunday when it won 138 of parliament’s 199 seats, giving it broad authority to undo much of the legislation that allowed Orbán to stack the courts, manipulate the electoral system, crack down on press freedom and discriminate against the LGBTQ+ community.

Still, there are potential pitfalls that could stand in the way of the radical changes many Hungarians had hoped for.

Magyar’s victory was met with jubilation on the streets of Budapest late Sunday with tens of thousands, many of them young people, celebrating what they view as a ray of hope that Orbán’s loss will make Hungary freer, happier and firmly rooted within the fold of European democracies.

On streets and avenues across the capital, drivers blared car horns and cranked up anti-government songs while people marching in the streets chanted and screamed.

During the celebrations, Adrien Rixer said he’d come back to Hungary from his home in London “because I really wanted to make my vote count, and I’m over the moon.”

“Finally I can say that I’m a proud Hungarian, finally after 16 years,” he said.

Many Hungarians, and others across Europe who were closely watching the election, had feared that a simple majority for Tisza would have been inadequate to truly transform Orbán’s system.

Yet others remain uncertain about what the authority of a two-thirds majority will bring, with some uneasy about taking such a mandate from Orbán and delivering it to his opponent.

“Its hard to see that with two-thirds that it’s going to be a fair government, but we will see,” said reveller Dániel Kovács. “Lets hope that it’s going to be a promising four years.”

The election win for Magyar and Tisza was without precedent in Hungary’s post-Communist history: They received more votes and more parliamentary seats than any party ever had before.

Bulcsú Hunyadi, an analyst with the Budapest-based think tank Political Capital, said that while Tisza’s constitutional majority gives it broad powers to roll back many of Orbán’s policies, Hungary’s key institutions are “led by people who are cemented in their position for many years.”

As part of his broader effort to consolidate control over Hungary’s democratic system, Orbán installed loyal allies at the helm of key institutions, from the media authority to the public prosecutor’s office and the Constitutional Court.

In several cases, mandates were extended or new appointments pushed through before existing terms had expired — moves that effectively kept loyal leadership locked in place for years, well beyond any potential change in government.

In his victory speech on Sunday, Magyar called for such officials — including Hungary’s president — to step down of their own accord. Beyond that, Hunyadi said, “they don’t really have any other tools to remove these people.”

Magyar accuses Orbán and his government of mismanaging Hungary’s economy and social services, and overseeing unchecked corruption he says has led to the accumulation of extreme wealth within a small circle of well-connected insiders while leaving ordinary Hungarians behind.

He’s vowed to hold such abuses to account, and plans to create an Office for the Recovery and Protection of National Assets to reclaim what he says are Orbán’s allies’ ill-gotten gains.

Magyar campaigned heavily on a promise to bring home billions of euros in European Union funding that has been frozen to Hungary over corruption and rule-of-law concerns under Orbán. He’s also pledged to introduce the euro to Hungary by 2030 — something Orbán’s government long resisted.

Hunyadi, the analyst, said Magyar’s government will be under “tight pressure” by the EU to quickly carry out reforms in order to get access to those frozen funds that are badly needed by Hungary’s faltering economy.

“There are deadlines in terms of unfreezing the funds. They will have to deliver certain laws and reforms by August this year, which is only a few months away,” he said.

Tisza’s win raised hopes across the EU that a new government in Budapest would reverse Orbán’s antagonistic approach to Ukraine and his obstruction of efforts to assist the war-ravaged country as it defends against Russia’s full-scale invasion.

Orbán has used his veto power in the EU to stymie sanctions on Russia and block crucial funding to Kyiv. He’s also vowed never to allow talks on Ukraine joining the EU to resume.

In a statement on Monday, Ukrainian Foreign Minister Andrii Sybiha said Orbán’s election campaign, “which unfortunately was marked by manipulative rhetoric about Ukraine, is now behind us.”

“We expect that … the election results will also contribute to a normalization of political relations,” Sybiha said.