Brussels may have pencilled Montenegro and Albania as next in line for European Union membership, and Moldova’s electorate has handed down a clear pro-EU mandate. But one member state stands as an outsized obstacle to enlargement: Viktor Orbán’s Hungary.
As the war in Ukraine grinds on and the Kremlin pushes to expand its influence across former Soviet states, EU enlargement has moved from a long-term aspiration to a major item on the European agenda.
Yet the process that once symbolised Europe’s post-Cold War unity is now gridlocked. Under the EU’s unanimity rule, every member state must approve each step of enlargement, and that gives Hungarian Prime Minister Orbán an effective veto over the decision to admit Moldova and Ukraine as members. Hungary, which joined the EU in 2004, has used that power repeatedly, holding up Ukraine’s accession talks and pushing for concessions on other policy fronts.
“He [Orbán] has used blocking Ukraine as a sort of instrument to get more favours within the EU,” Andi Hoxhaj, lecturer in law at King's College London, told The Parliament.
Now, with candidate countries growing impatient and Moscow watching closely, the EU faces a pressing question: how to keep enlargement moving while one of its own keeps blocking the path.
Hungary’s selective enlargement diplomacy
Orbán’s stance on enlargement is less ideological than transactional. He has championed EU membership for a number of Western Balkans states, but only the ones aligned with his own political and economic interests.
“When he says that he supports the Balkans, he definitely supports Serbia and Bosnia and Herzegovina, but especially Serbia,” said Tefta Kelmendi, an independent policy analyst specialising in enlargement. “This is really immediately linked to his personal links with some of the actors in these two countries.”
Indeed, Hungary and Serbia are bound by major energy deals. A new oil pipeline connecting the two countries could, by 2028, meet all of Serbia’s oil needs, while Hungarian energy giant MVM recently became the majority owner of two Serbian firms. In Bosnia’s Serb entity, Republika Srpska, Budapest has also invested in several energy projects.
But Orbán’s regional enthusiasm stops at Ukraine’s border. Budapest has been the loudest opponent of Ukraine’s bid, arguing it could drag the bloc into war and drain EU finances.
Critics have repeatedly referred to Orbán as Russian President Vladimir Putin’s “trojan horse” in the EU. He is one of the only EU heads of state to have kept close ties to the Kremlin following its full-scale invasion of Ukraine in 2022.
“If Ukrainians become members of the union, this war will also become our war,” Orbán told reporters at a European Council meeting in Brussels this year. “And we do not want that.”
Behind the rhetoric lies a fear of losing money. Between 2014 and 2020, Budapest received roughly €25 billion in EU cohesion and agricultural funds — nearly 4% of its annual GDP — making Brussels the single largest source of public investment in the country. Kyiv’s accession could divert part of the EU common budget away from Hungary.
Orbán has made a habit of turning veto threats into bargaining chips. In 2023, he left the Council room to let the remaining 26 leaders open talks with Ukraine — just after the Commission unfroze €10.2 billion in EU funds to Hungary.
“The EU has blocked funds from Budapest before, on grounds of corruption, judiciary independence and misuse of public funds," said Hoxhaj. “So I think he will continue to play the game.”
The same tactic surfaced amid Sweden’s NATO accession, which Hungary approved only after clinching a deal to buy four Saab Gripen fighter jets.
Now, with Hungarian elections looming and Orbán facing growing domestic discontent, he has doubled down on anti-Brussels rhetoric, portraying EU support for Ukraine as a ploy against his government.
“Let’s be under no illusions: Brussels and Ukraine are jointly building up a puppet government [in Hungary],” Orbán said in June. “They want to change Hungary’s policy towards Ukraine after the next elections, or even sooner.”
Moldova, collateral damage?
Moldova and Ukraine have been at the heart of the EU’s renewed enlargement drive since 2022. Their bids are closely intertwined: Brussels has treated them as part of the same track, following a long-standing practice of pairing candidate countries from the same region.
In 2004, eight former Soviet-bloc states joined the EU together as part of Europe’s post-Cold War reunification, followed by Bulgaria and Romania in 2007. Yet that regional approach hasn’t always worked. Accession for Albania and North Macedonia were linked for many years, yet Greece vetoed North Macedonia over a long-standing dispute about the country’s name, derailing Albania’s accession in the process.
“The EU didn't learn any lessons from the Balkans in this regard,” said Kelmendi. “First off, because of potential bilateral conflicts between different countries. And second of all because one can stagnate and then hold hostage to the other.” He added: “Accession needs to be decoupled.”
Now, blocking Ukraine risks doing the same for Moldova, whose EU ambitions are gaining fresh momentum. Last month, President Maia Sandu’s pro-EU Party of Action and Solidarity won a decisive parliamentary majority, as voters backed a future in the EU amid rising pressure from Moscow.
Even so, EU officials have said they won’t decouple Moldova and Ukraine, for now, warning that separating the two would play into Russia’s goals to destabilise the region, as treating them together projects unity and limits Moscow’s room to interfere.
Orbán, meanwhile, says he supports Moldova’s accession — seeing it as providing a much-needed workforce to the EU — yet his continued obstruction of Ukraine risks undercutting Moldova’s clear pro-European mandate.
Can Brussels outflank Budapest?
As Hungary continues to wield its veto, Brussels is weighing creative workarounds.
One idea gaining traction is replacing unanimity in foreign policy and enlargement policy with qualified majority voting — in which at least 55% of member states representing at least 65% of the EU’s population could approve decisions.
It’s an ambitious fix that would require amending the EU’s founding treaties — analysts say it could involve rewriting more than 70 provisions — and faces resistance from smaller member states wary of losing influence. Hungary, unsurprisingly, has flatly rejected it.
To Hoxhaj, such a proposal makes sense as the next enlargement will push the bloc across the 30-member mark, making consensus all the more elusive.
Another option floated is a form of “semi-membership,” offering candidate countries deeper integration without full voting rights. But this halfway house has drawn sharp criticism.
"If we speak about EU membership, it has to be fully-fledged,” said Ukrainian President Volodymyr Zelenskyy at a Euronews event last week. “In my opinion, you cannot be a 'semi' or 'demi' member of the EU.”
European Commissioner for Enlargement Marta Kos has echoed that stance, rejecting a different "class of membership."
“Proposals of some kind of middle ground are not good for enlargement credibility,” said Kelmendi. “We don’t need to come up with these very weak proposals.”
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