By-Elections

By-elections are where tactical voting matters most — one seat, one decision, and a result that carries national weight. Here is where the right-of-centre vote is at risk of splitting, and which party to back.

Upcoming by-elections

Contests where a poll has been called. Parliamentary by-elections are listed first, followed by mayoral and council contests in date order.

Recommendations are based on recent electoral performance in the area — how each party polled when the seat was last contested, how the surrounding council has voted since, and current national and regional polling.

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Where the split has already cost us

These are real by-election results, not projections. In each case the right-of-centre parties’ combined vote is set against the total of the party that actually won the seat.

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Parliamentary figures are projections from the 2024 result, current polling and published MRP polls — the same model used across this site. By-elections routinely produce much larger swings than any national model predicts, so treat these as a guide to where the vote splits, not as a forecast of the result. Council and mayoral recommendations are editorial judgement: the model covers Westminster constituencies only. Council by-election figures are published as vote shares rather than per-party counts, so vote gaps derived from them are shown as approximate.