The EU could deny future member states veto rights for several years in an attempt to make enlargement more politically acceptable as the bloc undergoes a push to admit new countries before the end of the decade.

Under plans being considered by the European Commission, prospective member states – such as Moldova and western Balkan countries – would not, on joining the EU, have the automatic right to veto foreign policy decisions or other issues agreed by unanimity, such as taxation.

The idea is especially pertinent for Montenegro, the frontrunner among nine official EU candidate countries. The former Yugoslav republic of 624,000 people is vying to become the EU’s 28th member state by 2028. This month a technical group tasked with drafting Montenegro’s accession treaty met for the first time, a sign that the 14-year negotiations were entering the final stages.

Against this backdrop, EU officials are considering safeguards on new joiners to prevent decisions being blocked by one member state, according to four EU sources. The idea emerged after a bruising experience with Hungary, whose previous pro-Russian government led by Viktor Orbán vetoed several big EU decisions, notably a €90bn loan for Ukraine.

A time-limited ban on veto powers could be written into Montenegro’s accession treaty, which would serve as a template for others waiting in the wings.

The safeguard is considered to be legally borderline and could only be introduced for a temporary period in order to avoid creating second-class EU members.

In a separate development, Germany’s chancellor, Friedrich Merz, wrote to EU leaders last week calling for “innovative solutions” to accelerate EU accession for western Balkan countries. In a letter describing EU enlargement as a “geopolitical necessity” Merz also called for “associate membership for Ukraine” as a “decisive step on Ukraine’s path to full membership”.

Associate membership for Ukraine would mean participation in EU meetings and representation in the bloc’s institutions without voting rights. Germany’s proposal, Merz wrote, “reflects Ukraine’s particular situation, a country at war” and would “facilitate the ongoing peace talks”.

Ukraine’s president, Volodymyr Zelenskyy, rejected this idea: “Ukraine’s place in the European Union must also be complete – full and equal,” he wrote on social media after Merz’s letter became public.

EU enlargement had almost ground to a halt until Russia’s full-scale invasion of Ukraine in 2022 injected new urgency into membership talks with eastern neighbours. The commission said last year it could admit new members by 2030, identifying Montenegro and Albania as the frontrunners, while praising Moldova’s fast progress and suggesting that EU membership could be a security guarantee for Ukraine.

A delay on veto powers is one of several safeguards being discussed in order to make EU enlargement easier to accept.

Existing EU member states must agree unanimously on admitting new countries. Officials are particularly concerned about ratification in France, where presidential elections will be held in 2027 and scepticism about EU expansion is increasing – a recent Eurobarometer survey found that only 43% of French respondents favoured EU enlargement, but that 48% were against.

EU sources argue there is a need for creative thinking to make enlargement happen, especially in the western Balkans, a region of 17.4 million people, where Russia and China are trying to gain influence.

One EU diplomat said delaying veto rights was one of the “constructive solutions” being considered as part of a process of “thinking creatively” on EU enlargement. A second diplomat said: “There is a debate on how to ensure that a larger enlargement would be beneficial for both the candidate countries and the EU itself. The ideas relating to internal reforms and different features of the accession treaties are all part of this.”

Germany has led efforts for internal EU reform, such as abolishing vetoes in foreign policy, fearing that an unreformed union of 35+ countries would be a recipe for gridlock. The German foreign minister, Johann Wadephul, said earlier this month that “a union with 33, 34 or 35 member states cannot simply continue to operate according to the same approach that was designed for a much smaller group”.

But the EU executive fears that waiting for consensus on EU reforms, which could require treaty change, could put enlargement on the backburner.

Among candidate countries, Ukraine is considered to be distinct because of its size, its war with Russia and the vast costs of reconstruction. The total cost of rebuilding Ukraine was estimated at $588bn as of 21 December 2025, three times the size of its economy.

EU officials think Ukraine is on track to technically complete its accession process in four years, but see the entry date as a political question tied to a peace settlement.

Engjellushe Morina, a senior policy fellow at the European Council on Foreign Relations, a thinktank, said a temporary block on veto powers was “not so drastic” and would be used by politicians to sell enlargement.

“I wouldn’t be surprised that we see something like this in Montenegro’s treaty. And this would be a blueprint for other member states for new members. This will be one of the things that politicians, policymakers will come out and say: ‘look we are doing this and that as safeguards and we are taking these precautionary measures’. That’s the logic.”

The idea was also a way of insulating the union from a new member state that takes a drastically different direction after accession, for example the election of a pro-Russian government in Montenegro. The commission and EU member states want to “waterproof the union from these hypothetical situations”, she said.

A source from the Montenegrin government said its goal remained full EU membership, “with all the rights and responsibilities that come with being an equal member state”, while adding that Montenegro “does not oppose safeguard mechanisms and believes they can play a constructive role in ensuring the sustainability of reforms even after accession”.