Built from English-Wikipedia "Opinion polling for the … election" articles. Each row carries (i) the source URL of the original poll publication as cited in the Wikipedia cell and (ii) a pinned ?oldid=<revid> permalink to the Wikipedia revision. Polls inherit Wikipedia's CC-BY-SA 4.0 licence.
31 countries, ~278k voting-intention poll-party observations. Italy, UK, Germany, Spain, Greece, Poland, Portugal span 2005–2026 densely. Norway, Netherlands, Sweden, Denmark, Czechia, Austria, Slovenia, Slovakia, Hungary, Estonia cover roughly 2010 onwards. France presidential is candidate-keyed and ends in 2022; French legislative is sparser. Smaller / single-cycle countries (Ireland, Finland, Iceland, Bulgaria, Lithuania, Latvia, Romania, Malta, Switzerland, Croatia, Cyprus, Luxembourg) cover only their most recent 1–2 cycles. Belgium is not included.
The Italian scrape was cross-checked against the official Italian government poll register (via the ondata mirror of sondaggipoliticoelettorali.it) on 2,523 overlapping (year-month × pollster × party) cells:
The other countries have not been validated against an external source.
All values are voting-intention vote shares on valid votes (excluding "don't know" and blank/spoilt where Wikipedia reports them separately; those columns are renormalized to 100%). Non-vote-intention columns that Wikipedia editors sometimes place adjacent to the vote-share table are filtered out: approval / disapproval ratings, leader-preference items (e.g. the German Kanzlerfrage), seat or probability forecasts, "lead" margins, and residual "Others" buckets. Coalition-aggregate rows are dropped when the component-party rows are available for the same poll.
The line on the chart is a 21-day rolling mean per party; the faded dots show individual polls.
Each poll-party row carries a stable Party Facts id (97.1% of voting-intention rows). Chart labels and aggregation are keyed by Party Facts' canonical English name — so variant Wikipedia shorts that map to the same Party Facts id (e.g. Italy's LN and Lega) collapse onto one continuous chart line. Hover tooltips give the native-language name. Parties not yet in Party Facts (~2.9%; e.g. ES Sumar, IT AVS, PL UnitedRight) fall back to their Wikipedia short label and carry a stable europolls_party_id namespaced as EU:{country}:{party_short}.
Forte, G. (2026). Europolls: a database of opinion polls. github.com/gfrt0/europolls