Berlin-based Civil Liberties Union for Europe’s annual report found that challenges to the rule of law were sporadic in old democracies with mainstream parties in power, including Germany and France, but that deterioration in countries with far-right parties in power, like Italy and Sweden, risked becoming systemic.

In countries more recently admitted to the EU, such as Slovakia, Slovenia and Poland, the rule of law “can swing rapidly – either towards recovery or decline”.

The 600-page report, used by the European Commission in its rule-of-law monitoring, indicates that the EU must act to prevent backsliding.

Balázs Dénes, executive director of the Civil Liberties Union for Europe, said: “The bottom line is that the commission, the entire EU, are sitting on a very powerful toolbox but they are reluctant to use it quickly and assertively. We are alarmed by the lack of serious analysis of what is actually going on in some places.”

In France, the pension changes of last year were “enacted in a manifestly undemocratic legislative process” after the government availed itself of special constitutional powers.

Journalists in Germany meanwhile face prosecution if they publish judicial decisions that are not publicly accessible.

Italy and Sweden have seen incursions into the rule of law in the justice system, media freedom and human rights.

Finally, Slovakia’s populist prime minister, Robert Fico, was “systematically dismantling democratic structures”, the report found.