European governments face an unprecedented financing challenge as rising spending demands linked to ageing populations, the energy transition and defence threaten to place public finances under severe strain, according to a new paper released by the International Monetary Fund (IMF).

The IMF’s European department said public spending across the region is expected to increase by close to 5 per cent of GDP on average by 2040, while many countries are already burdened with elevated public debt and face limited political support for higher taxes, spending cuts or privatisation.

The report examines how European governments can meet these growing demands while preserving fiscal sustainability, warning that failing to act would have profound consequences for public finances.

According to the IMF, public debt in the average European economy would double over the next 15 years if current trends continue, with average debt levels across the continent reaching around 130 per cent of GDP by 2040.

The paper argues that maintaining sustainable debt must remain the overriding objective and uses a reference debt path of no more than 90 per cent of GDP over the long term as a benchmark for the average European economy.

The IMF explained that while some countries may require lower debt levels because of market pressures or national circumstances, the 90 per cent benchmark reflects the greater debt-carrying capacity many European economies have developed over the past three decades.

The report asks whether a realistic combination of policy measures can shift countries away from what it describes as an unsustainable debt trajectory towards a sustainable path.

To achieve this, the IMF proposes a three-pillar strategy centred on structural reforms, medium-term fiscal consolidation and, where necessary, a broader reassessment of the role of government.

The first pillar focuses on structural reforms designed to reduce debt pressures by boosting economic growth, improving governments’ ability to manage spending demands, addressing major cost drivers such as pensions and transferring a greater share of spending responsibilities to the European Union.

The IMF said productivity-enhancing reforms would include changes to national product and labour markets, relatively modest measures to strengthen the EU single market, pension reforms, initiatives to encourage private investment and greater centralisation of some spending at EU level.

Although these reforms would take time to deliver measurable fiscal benefits, with most gains expected to emerge during the decade following a five-year implementation period, the IMF believes they could have a substantial long-term impact.

According to the paper, even a moderate package of reforms could eliminate roughly one-third of the gap between Europe’s projected debt path and a sustainable trajectory.

The IMF said simulations indicate that pension reforms and measures to improve domestic productivity are particularly important in easing future fiscal pressures.

It added that more ambitious reforms would further reduce the scale of fiscal tightening required to maintain sustainable debt.

However, the IMF stressed that reforms alone will not be enough to meet rising spending demands across most European countries.

The report estimates that nearly three-quarters of European countries will still require fiscal consolidation even if moderate structural reforms are introduced.

Without reforms, the average European country would need cumulative fiscal consolidation equal to around 5 per cent of GDP over five years, or approximately 1 per cent of GDP annually, according to the analysis.

With the moderate reform package outlined in the report, the required adjustment falls to around 3.5 per cent of GDP over the same period, equivalent to roughly 0.75 per cent of GDP each year.

While still substantial, the IMF said this level of adjustment is more consistent with historical experience.

The report added that the balance between reforms and fiscal consolidation will ultimately depend on each country’s political priorities, social preferences and ability to implement change.

The IMF also warned that delivering such fiscal consolidation would be challenging and would require careful policy design to protect both economic growth and social fairness.

It said sizeable fiscal tightening over a relatively short period could weigh on economic activity, particularly where economies remain below potential, financial conditions are restrictive or monetary policy has limited scope to offset weaker government spending.

The report also cautioned that poorly targeted cuts to public services or welfare payments, along with increases in regressive taxes, could disproportionately affect lower-income households, undermine social cohesion and increase the risk of reform fatigue and policy reversals.

To reduce these risks, the IMF argues that fiscal strategies should prioritise growth-friendly and equitable policies, safeguard high-quality public investment, improve spending efficiency, broaden tax bases rather than relying solely on higher tax rates, and strengthen support mechanisms for vulnerable groups.

Even if countries pursue ambitious reforms and disciplined fiscal policies, the IMF believes many heavily indebted governments will still face difficult decisions about the future scope of public services.

The paper estimates that around one-quarter of European countries would require fiscal consolidation beyond anything achieved historically, even after implementing moderate reforms.

For those countries, the IMF said a wider debate about the long-term sustainability of Europe’s socioeconomic model, including its extensive welfare systems and generous public services, appears unavoidable.

The report suggests governments may eventually need to reconsider the boundaries of the state by transferring some financing responsibilities from the public to the private sector, tightening eligibility for benefits, reforming subsidies, introducing higher user charges for higher-income groups and restructuring or privatising state-owned enterprises while protecting essential services and vulnerable households.

According to the IMF, aligning public financing for healthcare, education, infrastructure and climate investment with the average levels seen across the Organisation for Economic Co-operation and Development could generate savings of close to 3 per cent of GDP for the average European country.

However, the IMF warned that such changes would go to the heart of Europe’s social contract and said they would require careful deliberation, extensive consultation, clear communication and well-sequenced medium-term implementation plans to succeed.