Andreas Johansson Heinö // 22 October 2026

Almost one in three European voters now backs a challenger party. The fifth edition of the Authoritarian Populism Index, published by Timbro and EPICENTER, finds that combined support for populist, authoritarian and extremist parties on the left and right has reached a record 32.6%. That is roughly three times the level seen for most of the post-war era. Covering more than 260 parties in 31 European democracies, with electoral data from 1945 to October 2026, the Index shows that challengers win more than 20% of the vote in 26 of those countries.

The radical right drives most of this rise and has proved resilient, retaining voters rather than fading after a protest surge. The radical left has edged up recently but remains well below its post-war strength. On the mainstream side, Christian democrats and social democrats have suffered the heaviest losses, while liberals are holding close to their best-ever results.

Challenger parties are also no longer outsiders. By summer 2026 they sat in 11 of the 31 governments. The record shows that office moderates some of them, emboldens others and brings down still others’ coalitions. An expanded analysis of 76 parties finds most are culturally conservative and split evenly between economic left and right. Outright EU exit is now a minority position, with many seeking to reshape the Union from within. Relations with Russia and the United States have become a new fault line. The main concern remains democracy itself: 18 parties are classified as highly authoritarian.

The main conclusions of the publication are:

• Challenger parties have never been stronger. Almost one in three European voters (32.6%) now backs a populist, authoritarian or extremist party, and challengers win more than 20% of the vote in 26 of the 31 countries covered.
• The radical right is driving the rise and has become a permanent feature of European politics. Its support has grown steadily for three decades and held up even after the refugee crisis receded. The radical left, despite a recent uptick, remains well below its post-war strength.
• The old pillars of post-war politics are weakening. Social democrats have lost more than four in ten voters since 2000, and Christian democrats have declined steadily since the 1970s. Liberal parties, by contrast, are holding close to their record levels.
• Government participation does not automatically moderate challengers. Challenger parties sat in 11 of 31 governments by summer 2026. Office has tamed some, such as the Sweden Democrats and the Finns Party, but emboldened others or led to collapsed coalitions, as in the Netherlands.
• Most challengers now want to reshape the EU rather than leave it. Of the 76 parties examined, 20 are hard eurosceptic, while many seek to redirect EU cooperation towards migration control, border protection and national sovereignty.
• Russia and the United States have become new dividing lines. Attitudes to Moscow, Ukraine and Trump’s MAGA movement increasingly split the European radical right, and American backing has not delivered the electoral boost many expected.
• Authoritarianism remains the main cause for concern. Eighteen parties are classified as highly authoritarian, including Fidesz, PiS and Smer, which have already weakened checks and balances in government.