COPENHAGEN, Denmark — Last year had the worst decline in credible elections and parliamentary oversight in almost a half-century, driven by government intimidation, foreign interference, disinformation and the misuse of artificial intelligence in campaigns, an organization promoting democracy said Tuesday.

The International Institute for Democracy and Electoral Assistance, or International IDEA, said election credibility is threatened by turnout dropping and results are increasingly being contested. One in three elections are being disputed in some way, it said.