Montenegro tests EU enlargement timetable at Brussels summit

Montenegro’s file moves from chapters to treaty drafting

Montenegro’s case has advanced beyond routine chapter management. The Council’s summit agenda explicitly refers to “ongoing work on the accession treaty with Montenegro,” giving the country a distinct place in the October European Council debate.¹ The 29th EU-Montenegro Accession Conference, held on October 12 in Luxembourg, provisionally closed chapters 17, 18 and 19 and recorded the Irish Council presidency’s view that enlargement remains a geopolitical priority.²

The Council press release confirms that Montenegro has opened all 33 negotiating chapters and provisionally closed 21. It also stresses a key caveat: provisional closures are not final until an overall agreement is reached, and the EU may return to chapters if needed.³

That means the end-2026 target is politically meaningful but not self-executing. Each remaining chapter still requires member-state agreement, and the final accession treaty would need to be signed and ratified.

The legal work is already becoming visible. The EU common position on Chapter 17 includes draft treaty-related language on Montenegro’s use of the euro, one of the most technically sensitive elements of its accession. The document says Montenegro would join the Economic and Monetary Union on accession as a member state with a derogation. It would be exceptionally allowed to continue using the euro as its sole legal tender under national law, but would not receive euro-area rights or obligations until the derogation is lifted.⁴

The document also sets out an adjusted convergence assessment framework, including participation in the exchange-rate mechanism for at least two consecutive years before a positive euro-adoption assessment.⁴

That level of drafting matters because it shifts the debate from broad geopolitical language to accession engineering. It suggests EU institutions are preparing legal accommodations for Montenegro’s specific circumstances while preserving the principle that euro-area status follows the Union’s treaty process, rather than unilateral euro use.

The timetable is ambitious, but still political

Podgorica’s goal is to provisionally close all remaining chapters by the end of 2026 and move toward signing an accession treaty in 2027, according to the Montenegrin government’s account of Prime Minister Milojko Spajić’s position after the October 12 conference.⁵ Regional reporting says 12 chapters remain, and Vreme reported that 10 are already in procedure.⁸

The New Union Post reported that the October 12 conference was tied to wider accession-treaty work, a €3.2 billion financial package for Montenegro’s accession, the expected handling of Chapter 33 on financial and budgetary provisions, and a possible 2028 membership horizon.⁷

That sequencing shows why the European Council discussion matters. Closing chapters is one track; preparing the Union’s budgetary and institutional commitments for a new member is another.

Chapter 33 is likely to be especially consequential because it deals with financial and budgetary provisions. It sits at the intersection of accession and the next multiannual financial framework, which the European Council will also discuss at the October summit.¹⁷ If leaders want Montenegro to become the EU’s next member within a defined period, they will need to align the accession calendar with budget planning for the 2028-2034 cycle.

Domestic consensus remains a condition

The Brussels timetable also depends on Podgorica’s ability to sustain cross-party support for final reforms. Vijesti reported that Enlargement Commissioner Marta Kos warned Montenegro’s government and opposition to cooperate and take responsibility for urgent decisions, saying failure to do so would risk the country’s EU future at the point when it is closest to membership.⁶ Vreme similarly reported that Kos backed the goal of closing all chapters by year-end but made the outcome conditional on cooperation between the government and opposition.⁸

Those warnings point to the remaining political weight of rule-of-law and constitutional questions. Montenegro has moved fastest among Western Balkan candidates, but the final stage of accession is not a purely technical exercise. It requires durable political consensus in Podgorica, unanimous approval among EU member states, and confidence that reforms will be implemented, not merely negotiated.

Bilateral issues also remain relevant. Vijesti reported Spajić’s statement that Croatia’s support was necessary for the latest chapter closures and that Podgorica and Zagreb continue to discuss unresolved questions.⁶ For enlargement watchers, that is a reminder that even a frontrunner can be slowed by member-state concerns outside the formal chapter checklist.

The wider-Union question

Montenegro is becoming the EU’s near-term test case because it is small enough for accession to be manageable, advanced enough for treaty work to be credible, and politically significant enough to test whether the Union’s post-Ukraine enlargement rhetoric can produce an actual accession sequence.

But the October European Council debate will also expose the larger constraint. Leaders are not discussing enlargement in isolation. They are discussing it beside the next long-term budget, competitiveness pressures, Ukraine, migration, security and institutional reform.¹

That agenda structure reflects the central bargain now facing member states: enlargement requires internal preparation, but internal preparation can also become a reason to delay enlargement.

A strong signal from leaders would not itself admit Montenegro. It could, however, clarify whether the end-2026 negotiations target is the start of a political timetable toward membership or simply another milestone subject to later institutional and budgetary bargaining.

A weaker signal would leave Montenegro’s progress intact on paper but reinforce doubts about whether the EU is ready to convert Western Balkans accession into a dated, treaty-based commitment.

For now, the Council’s own documents show both momentum and caution. Montenegro has closed 21 chapters, treaty-related language is being drafted, and leaders will discuss the end-2026 target at summit level.¹³⁴ Yet provisional chapter closures can be reopened, remaining reforms require domestic consensus, and the EU’s own financial and governance settlement is still in play.

Montenegro may be closest to the door, but the October summit will indicate whether member states are ready to unlock it.