Peter Magyar has claimed a historic victory in Hungary’s elections, ousting Trump and Putin ally Viktor Orbán after 16 years in power.
Hungarians took to the polls on Sunday in what Mr Magyar’s Tisza party called a “now or never” moment to topple Europe’s longest-serving leader.
Just two hours after polls closed, Mr Magyar posted on Facebook that Mr Orbán had “congratulated me on the phone on our victory”, with 45.7 per cent of the count predicting Tisza were projected to win 135 mandates in the 199-seat parliament.
Speaking to supporters in Budapest, Mr Orbán said the result was “painful” and vowed: "We are going to serve the Hungarian nation and our homeland from opposition as well."
Prime Minister Sir Keir Starmer has congratulated Mr Magyar on his victor, hailing a “historic moment, not only for Hungary, but for European democracy”.
Pollsters predicted a record voter turnout, with Hungarian television showing long queues outside some voting stations in Budapest.

Mr Orbán, who has been in power for 16 years, is known as a conservative anti-globalist whose ties to Vladimir Putin and the Trump administration have seen become a global figure in far-right politics.
His opponent Mr Magyar, a former Orbán loyalist, has quickly gained popularity through campaigning on frustrations over altering public health care and transportation sectors and what he describes as rampant government corruption.
Queues of voters were pictured outside polling stations across the country as record numbers of Hungarians cast their ballots.
An end to Mr Orbán’s period in government has significant implications not only for Hungary, but for the European Union, Ukraine and beyond.
It would likely spell an end to Hungary's adversarial role inside the EU, possibly opening the way for a 90 billion euro ($105 billion) loan to war-battered Ukraine blocked by Mr Orbán.
Defeat for Mr Orbán 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.

Mr Orbán'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 the White House.
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.
Mr Orbán, a eurosceptic, carved out a model of an "illiberal democracy" seen as a blueprint by Trump's Make America Great Again (MAGA) movement and its admirers in Europe.
But many Hungarians have grown increasingly weary of Mr Orbán, 62, after three years of economic stagnation and soaring living costs as well as reports of oligarchs close to the government amassing more wealth.
Tisza's leader Magyar appears to have successfully tapped into this frustration.
Casting his vote for Tisza in the Hungarian capital, Mihaly Bacsi, 27, said the country needed change.
"We need an improvement in public mood, there is too much tension in many areas and the current government only fuels these sentiments," he said., a eurosceptic, carved out a model of an "illiberal democracy" seen as a blueprint by Trump's Make America Great Again (MAGA) movement and its admirers in Europe.
But many Hungarians have grown increasingly weary of Mr Orbán, 62, after three years of economic stagnation and soaring living costs as well as reports of oligarchs close to the government amassing more wealth.
Tisza's leader Magyar appears to have successfully tapped into this frustration.
Casting his vote for Tisza in the Hungarian capital, Mihaly Bacsi, 27, said the country needed change.
"We need an improvement in public mood, there is too much tension in many areas and the current government only fuels these sentiments," he said.
Ahead of the vote, opinion polls showed Mr Orbán's Fidesz party trailing Mr Magyar's upstart centre-right opposition Tisza party by 7-9 percentage points, with Tisza at around 38-41 per cent. Pollsters predicted record voter turnout of well over 70 per cent.
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