Transparency
Sources & methodology
Ayes and Noes brings together official UK parliamentary data with a small amount of clearly labelled local analysis. This page explains exactly where each kind of information comes from, how the derived measures are produced, and where the data has known limits. Every data page on the site also carries its own source note linking back to the relevant source below.
Official UK Parliament data
The core of the site is sourced directly from UK Parliament's open APIs and refreshed on a regular schedule.
House of Commons divisions: vote titles and dates, Aye and No counts, results, and each MP's recorded vote, including tellers.
Current and former MPs, party affiliation and colours, constituencies, biography snapshots, registered interests, member photographs, and constituency boundary geometry.
Bills before Parliament, their type and primary sponsor, and the linkage between bills and related Commons divisions.
Debate appearance summaries for current MPs, used to count and link Hansard debate activity.
Written parliamentary questions tabled by MPs.
Oral parliamentary questions tabled by MPs.
Other official and open sources
Published Total Spend figures from the Independent Parliamentary Standards Authority, used for MP and party expenses.
Postcode-to-constituency lookup that powers the Find your MP feature. Postcodes are not stored.
Historical general election seat totals by party (2010–2024), used for party seat timelines.
Locally derived analysis
Some features are produced by Ayes and Noes from the official data above. These are analysis, not official Parliament categorisations, and are labelled as such wherever they appear.
Topic tags
Divisions, debates, and questions are tagged with topics using a local set of keyword rules applied to titles. Parliament does not provide a topic field, so these tags are indicative and may miss or over-match a title.
Bill and division linkage
Divisions are linked to bills by matching titles, including former titles and stem matching such as "X Bill" to "X Act". Amendment- and clause-level division titles often cannot be matched and are left unlinked.
Voting alignment
MP-to-MP agreement is the share of divisions where both MPs recorded a comparable Aye or No vote and chose the same option. Absences, abstentions, tellers, and missing votes are excluded, and every score is shown with its shared-vote count.
Voted against party
An MP is shown as voting against their party when their recorded vote differed from the majority recorded vote of their party in that division. It reflects the recorded vote only and does not describe the formal whip.
Known limitations
- Topic tagging is local and keyword-based, not an official Parliament classification.
- Bill matching is title-based, so some bill-related divisions remain unlinked.
- "Did not vote" means no recorded Aye or No vote was imported for that MP in that division. It does not on its own explain the reason, which may include illness, pairing, ministerial duties, or acting as a teller.
- Tellers are recorded as Aye or No with a teller flag; published count totals and the sum of individual votes can differ slightly because of how tellers are reported.
- Historical constituency boundaries change between general elections, so older maps may not match present-day boundaries.
- Some Parliament API endpoints omit fields or return incomplete historical records. The site shows the available sourced data and avoids inferring unsupported facts.
- Sinn Féin MPs and the Speaker do not take part in Commons divisions in the usual way and are excluded from some participation-based measures.
Licence and attribution
Most parliamentary source material used by Ayes and Noes is made available under the Open Parliament Licence v3.0. Where the site links to external sources, their own terms and licences apply. Commons divisions are refreshed daily, current MPs weekly, and profile snapshots monthly or on demand. See the FAQ for more on how to read the data.