Can De Wever stop Belgium’s rising interest bill from becoming a debt snowball?

Belgium’s ten-year government-bond yield reached 3.83% on 21 August, according to the Belgian Debt Agency, bringing the cost of new federal borrowing to its highest territory in years as Prime Minister Bart De Wever

Person

Bart De Wever

Belgian prime minister leading the federal coalition and its autumn budget negotiations.

Why it matters

Belgian prime minister leading the federal coalition and its autumn budget negotiations.

About

Bart Albert Liliane De Wever is a Belgian politician who has served as the Prime Minister of Belgium since February 2025. From 2004 to 2025, De Wever had been the leader of the New Flemish Alliance (N-VA), a political party advocating Flemish independence. From January 2013 to February 2025, he was Mayor of Antwerp, following the 2012 municipal elections.

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The market move is not, by itself, a Belgian debt crisis. Yields have risen elsewhere in Europe, and Belgium continues to borrow normally. The Debt Agency’s figure nevertheless matters because the country must continually refinance part of a federal debt stock that stood at almost €575 billion at the end of July. A higher rate therefore feeds into public spending gradually, as old bonds mature and are replaced, rather than producing one immediate budget shock. That delay offers the government time, but it also makes the problem easy to underestimate.

The Federal Planning Bureau supplied the clearest explanation of the risk in its February 2026 outlook. It projected general-government debt rising from about 107% of gross domestic product in 2025 to 117% in 2029 and 122% in 2031 under policies decided at the time. Interest expenditure would increase by roughly one percentage point of GDP over five years. The bureau expected the average interest rate on the debt to remain below nominal economic growth until 2030, but not in 2031. Crossing that line would create the conditions for a self-reinforcing debt dynamic unless Belgium achieved a sufficiently strong primary balance — the budget balance before interest payments.

The bureau subsequently made its economic assumptions less favourable. Its June outlook, incorporating the effects of the conflict in the Middle East, put Belgian growth at just 0.7% in 2026 and the general-government deficit at 5.1% of GDP. It projected the deficit rising again thereafter and reaching 6.4% in 2031 without further measures. De Standaard highlighted the political trap in early August: weak growth makes the debt ratio harder to reduce, while abrupt tax increases or spending cuts can themselves weigh on demand and investment.

That is the mountain Devos says De Wever must now confront. The federal government formed in February 2025 by N-VA

De Wever’s frame is that structural reforms need time to raise employment and contain expenditure. Speaking in the Chamber of Representatives in May 2025, the Prime Minister acknowledged that more would ultimately be required to reach a structurally healthy budget. He has also argued that Belgium cannot reverse long-term deterioration in a single five-year term. That case has some institutional support: employment and pension reforms can produce savings slowly, and Belgium’s federal debt has a maturity structure that delays the full impact of higher market rates.

Independent watchdogs have nevertheless challenged important parts of the government’s arithmetic. In May 2025, the Belgian Court of Audit concluded that estimated returns from labour-market reforms were insufficiently substantiated and carried a high risk of being materially overstated. The federal opposition drew different lessons from that finding. Groen parliamentary leader Stefaan Van Hecke said the coalition’s budget rested on unrealistic feedback effects, while PS parliamentary leader Pierre-Yves Dermagne presented the report as evidence that the government’s consolidation strategy was failing. Vlaams Belang, from the opposite side of the political spectrum, has attacked the use of temporary financing and demanded deeper structural choices.

The trade-union frame is different again. The socialist ABVV-FGTB and Christian ACV-CSC have argued through protests and public campaigns that the coalition places too much of the adjustment on workers, benefit recipients and pensioners. They favour a larger contribution from capital and high wealth and question the priority given to rapidly increasing defence expenditure. Inside the coalition, that distributive argument runs between the French-speaking liberal MR, which resists heavier taxation and stresses spending restraint, and the Flemish socialist Vooruit, which insists that the strongest shoulders contribute. CD&V and Les Engagés occupy pivotal positions in attempts to turn those preferences into a compromise.

Responsibility is also divided across Belgium’s federal system. The federal level manages national debt, social security, defence and most personal taxation, so it bears the strongest exposure to ageing and interest costs. Regions and communities control substantial spending and revenue of their own, however, and their balances enter Belgium’s general-government figures under EU accounting. The European Commission

Organisation

European Commission

EU institution monitoring Belgium’s economic outlook and excessive-deficit procedure.

Why it matters

EU institution monitoring Belgium’s economic outlook and excessive-deficit procedure.

About

The European Commission (EC) is the executive cabinet of the European Union. It is composed of 27 members of the Commission corresponding to the number of member states, unless the European Council, by unanimous consent, decides to alter this number.

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The EU dimension is binding but not the immediate source of the market move. Belgium remains in the Union’s excessive-deficit procedure. In June 2026, the European Commission recommended that it respect the Council’s ceiling for net-expenditure growth while using the permitted flexibility for higher defence spending. The Commission’s spring forecast placed the deficit at 5.2% of GDP in both 2025 and 2026, well above the treaty reference of 3%, and expected debt to keep rising.

The next test will be whether De Wever can turn the autumn talks into measures that are both credibly quantified and politically sustainable. Investors will watch the updated deficit path, the treatment of defence expenditure and the extent to which recurring savings replace one-off receipts. Coalition partners will focus on who pays. What remains unknown is the precise package they will negotiate, how much of the reported €10 billion requirement must be delivered immediately, and whether weaker growth or another rise in yields will enlarge the bill before an agreement is reached.