What is tactical voting?
Tactical voting means voting for a candidate who is not necessarily the voter's first preference because the voter believes that candidate is better placed to affect the local result.
It is particularly associated with constituency-based systems such as First Past the Post.
In short
A voter might prefer Party A, but believe Party A has little chance of winning locally.
They may instead vote for Party B because they prefer B to the candidate they think is most likely to win.
That is tactical voting.
This page explains the concept. It does not recommend how anyone should vote.
Why can FPTP encourage tactical voting?
Only one candidate wins each constituency.
Votes for losing candidates do not contribute to a national pool that later allocates Commons seats proportionately.
Some voters therefore think about:
Who can realistically win here?
as well as:
Which party do I most prefer nationally?
That creates an incentive for tactical voting in competitive seats.
A simple hypothetical example
Suppose polling and previous results suggest:
| Candidate | Estimated support |
|---|---|
| A | 40% |
| B | 38% |
| C | 15% |
| Others | 7% |
A voter whose first preference is C may believe C is unlikely to win.
If that voter strongly prefers B to A, they might vote B tactically.
Another C supporter might still vote C because expressing their first preference matters more to them.
Both choices are legitimate.
Is tactical voting legal?
Yes.
Voters are free to choose any candidate on their ballot paper.
The Electoral Commission states that there is no law prohibiting websites from promoting tactical voting.
Organisations campaigning tactically can still become subject to ordinary election campaign spending and reporting rules.
Does tactical voting always work?
No.
A tactical decision depends on an assumption about which candidates are competitive.
That assumption can be wrong.
Reasons include:
- polling error;
- local change;
- turnout differences;
- several parties being competitive;
- voters reacting to tactical campaigns;
- outdated previous-election results.
A voter can therefore cast a tactical vote and still see a different candidate win.
Is tactical voting the same as a voting pact?
No.
Tactical voting describes an individual voter's decision.
An electoral pact involves political parties or candidates coordinating — for example, deciding not to stand against one another in certain places.
The two can interact, but they are different concepts.
Is tactical voting more important in marginal seats?
Potentially.
If a constituency is very close between two candidates, relatively small numbers of votes could affect the winner.
In a seat where one candidate has an enormous lead, tactical switching by a small number of voters is less likely to change the result.
This is why tactical-voting discussion tends to focus heavily on marginal constituencies.
Can tactical voting affect national seat totals?
Yes.
Under FPTP, every individual seat contributes one MP to the national result.
If tactical voting changes the winner in several constituencies, it can alter the overall Commons arithmetic even if the national vote-share effect appears small.
How can we know how much tactical voting occurred?
It is difficult to measure precisely.
A ballot paper records which candidate someone voted for, not whether that was their genuine first preference.
Researchers use:
- surveys;
- polling;
- voter interviews;
- statistical analysis.
But tactical motivation is not directly visible in the official count.
In Road to Number 10
The simulation includes Tactical Targeting because campaigns operating under FPTP care about where votes can change seats.
That is related to, but not identical to, tactical voting by individuals.
Campaign targeting asks:
Where should the party deploy resources?
Tactical voting asks:
Which candidate should an individual voter support given the local contest?