---
title: "Third Parties — AP Comp Gov Definition & Exam Guide"
description: "Third parties are parties outside the two dominant ones in a system. Key to AP Comp Gov Topic 4.3, from UK Lib Dems under FPTP to China's eight satellite parties."
canonical: "https://fiveable.me/ap-comp-gov/key-terms/third-parties"
type: "key-term"
subject: "AP Comparative Government"
unit: "Unit 4"
---

# Third Parties — AP Comp Gov Definition & Exam Guide

## Definition

In AP Comparative Government, third parties are political parties other than the two dominant parties in a two-party or two-party-dominant system; their ability to win seats or even legally compete reveals how electoral rules and regime type shape party systems (Topic 4.3).

## What It Is

Third parties are the parties left out when two big parties dominate a political system. In the UK, the Liberal Democrats are the classic example. They win a real share of the popular vote (often 10-12%), but the [first-past-the-post](/ap-comp-gov/key-terms/first-past-the-post "fv-autolink") system in House of Commons elections converts that into only a handful of seats. The party exists, campaigns, and earns votes, but the rules of the game keep it from translating support into power.

The AP course pushes you to compare how third parties fare across the six course countries, because the answer tells you what kind of party system you're looking at. In the UK, third parties are squeezed by electoral math. In Russia, they're squeezed by the state itself, through rules like rising [party registration requirements](/ap-comp-gov/unit-4/political-party-systems/study-guide/HNDifxoeF5hglhPzck7v "fv-autolink"), restrictions allowing only legally registered parties to run, and selective court decisions that disqualify candidates (PAU-4.A.3). In [China](/ap-comp-gov/review-by-country/china/study-guide/K0v3iydFqTXwWWKj "fv-autolink"), the situation is different again. Eight parties besides the Communist Party of China are legally allowed to exist, but only to broaden discussion and consultation, never to compete for governing power (PAU-4.A.2). So 'third party' can mean a genuine competitor at a disadvantage, or a decoration that makes a one-party state look pluralistic.

## Why It Matters

Third parties live in Topic 4.3 (What are Political Party Systems?) in [Unit 4](/ap-comp-gov/unit-4 "fv-autolink"), and they directly support learning objective [AP Comp Gov](/ap-comp-gov "fv-autolink") 4.3.A, which asks you to describe characteristics of party systems and party membership. Essential knowledge PAU-4.A.1 says party systems range from dominant party systems to multiparty systems across the course countries, and the treatment of third parties is the fastest diagnostic for placing a country on that spectrum. If third parties can compete and win seats proportional to their votes, you have a multiparty system. If they can run but rarely win, you have a two-party-dominant system shaped by electoral rules. If they can exist but never govern, you're looking at one-party or dominant-party rule. That comparison skill is exactly what the exam rewards, and it links Unit 4's party content back to Unit 1's regime classifications.

## Connections

### Dominant party systems (Unit 4)

A dominant party system is what you get when third parties are legal but structurally locked out of power. [Russia](/ap-comp-gov/key-terms/russia "fv-autolink")'s United Russia stays dominant not because rivals don't exist, but because registration rules and selective court decisions keep them from competing fairly (PAU-4.A.3).

### [Communist Party of China (Unit 4)](/ap-comp-gov/key-terms/communist-party-of-china)

China's eight non-Communist parties are the strangest version of third parties in the course. They exist by design to broaden consultation, but rules guarantee the CPC alone controls governing power to maintain centralism and order (PAU-4.A.2). Their existence does not make China multiparty.

### House of Commons and first-past-the-post (Unit 2)

The UK's single-member plurality elections are why the Liberal Democrats win 10-12% of votes but only 1-2% of seats. The electoral rule, not voter hostility, is what manufactures the two-party-dominant outcome. Electoral systems from Unit 4 explain institutional outcomes in [Unit 2](/ap-comp-gov/unit-2 "fv-autolink").

### Hybrid regimes (Unit 1)

How a state treats third parties is evidence for [regime](/ap-comp-gov/key-terms/regime "fv-autolink") classification. When Russia lets opposition parties exist on paper but uses legal tools to disqualify them, that gap between formal competition and real competition is the textbook signature of a hybrid regime.

## On the AP Exam

Third parties show up most often in questions about electoral rules and party system classification. A typical MCQ gives you data like the Liberal Democrats winning 10-12% of UK votes but only 1-2% of seats, then asks what that seat-vote disparity reveals about first-past-the-post and the party system. Your job is to connect the rule to the outcome, not just describe the numbers. The College Board has also tested party systems directly in free-response questions, including the 2019 Conceptual Analysis question (Q6) on different types of party systems and a 2017 SAQ. On FRQs, be ready to define a party system type, give a course-country example, and explain how rules (electoral formulas, registration requirements, legal bans) determine whether third parties can actually win power.

## Third parties vs Multiparty system

The existence of more than two parties does not make a system multiparty. The UK has the Liberal Democrats and others, but FPTP keeps it two-party-dominant. China has eight parties besides the CPC, yet it's a one-party state because only the CPC can govern. A true multiparty system requires multiple parties that can realistically win power, usually helped by proportional representation. Count the parties that can win, not the parties that exist.

## Key Takeaways

- Third parties are parties outside the two dominant ones in a two-party or two-party-dominant system, and their fate is a quick diagnostic for classifying any party system (PAU-4.A.1).
- In the UK, first-past-the-post elections punish third parties like the Liberal Democrats, who win 10-12% of votes but only 1-2% of House of Commons seats.
- China allows eight parties besides the Communist Party of China to exist, but only to broaden discussion and consultation, never to compete for governing power (PAU-4.A.2).
- Russia suppresses third-party competition through legal tools, including stricter registration requirements, letting only registered parties run, and selective court decisions disqualifying candidates (PAU-4.A.3).
- The presence of extra parties on a ballot doesn't make a system multiparty; what matters is whether those parties can realistically win and exercise power.
- On the exam, always connect third-party outcomes to the rules causing them, whether that's electoral math in democracies or state restrictions in authoritarian and hybrid regimes.

## FAQs

### What are third parties in AP Comparative Government?

Third parties are political parties other than the two dominant parties in a two-party or two-party-dominant system. In AP Comp Gov, the UK's Liberal Democrats are the go-to example, since they win a meaningful vote share but very few seats under first-past-the-post.

### Does China having eight other parties make it a multiparty system?

No. China is a one-party state because rules allow only the Communist Party of China to control governing power. The eight other parties exist solely to broaden discussion and consultation, which preserves the values of centralism and order (PAU-4.A.2).

### Why do third parties win so few seats in the UK?

First-past-the-post elections award each House of Commons seat to the single highest vote-getter in a district, so a party's support gets wasted unless it's geographically concentrated. That's why the Liberal Democrats can take 10-12% of the national vote but win only 1-2% of seats.

### How are third parties different from parties in a multiparty system?

In a multiparty system, several parties can realistically win power, often because proportional representation translates votes into seats fairly. Third parties exist in systems where two parties dominate, so they compete but rarely govern. The test is whether a party can win, not whether it exists.

### Are third parties banned in Russia?

Not formally, which is exactly the point. Russia maintains one-party dominance through legal mechanisms instead, including increasing party registration requirements, allowing only legally registered parties to run, and using selective court decisions to disqualify candidates (PAU-4.A.3).

## Related Study Guides

- [4.3 What are Political Party Systems?](/ap-comp-gov/unit-4/political-party-systems/study-guide/HNDifxoeF5hglhPzck7v)

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