---
title: "Coalition — AP Comp Gov Definition & Exam Guide"
description: "A coalition is an alliance of parties that together control a legislative majority, letting them form a government in parliamentary systems like the UK when no single party wins outright."
canonical: "https://fiveable.me/ap-comp-gov/key-terms/coalition"
type: "key-term"
subject: "AP Comparative Government"
unit: "Unit 2"
---

# Coalition — AP Comp Gov Definition & Exam Guide

## Definition

In AP Comparative Government, a coalition is an alliance of two or more political parties that together hold a majority of legislative seats, formed so they can create and sustain a government when no single party wins an outright majority, most commonly in parliamentary systems like the UK.

## What It Is

A coalition is what happens when no party wins big enough to govern alone. Two or more parties agree to combine their seats in the [legislature](/ap-comp-gov/key-terms/legislature "fv-autolink") so that, together, they control a majority and can form a government.

This matters most in parliamentary systems. Per the CED (PAU-3.A.1), parliamentary systems like the United Kingdom fuse lawmaking and executive functions, so the legislature itself selects the head of government. The prime minister needs majority support in parliament to take office and stay in office. If one party holds 326+ of the UK's 650 Commons seats, easy, it governs alone. If not, parties negotiate a coalition, like the Conservative-Liberal Democrat coalition of 2010-2015, trading cabinet posts and policy promises for votes. Presidential systems like [Mexico](/ap-comp-gov/review-by-country/mexico/study-guide/kBdQHh6UAoZ9orsL "fv-autolink") and [Nigeria](/ap-comp-gov/review-by-country/nigeria/study-guide/4uuIc1WGkOGZPbz5 "fv-autolink") don't need coalitions to form a government, because the executive is elected separately for a fixed term (PAU-3.A.2). The president takes office whether or not their party controls the legislature.

## Why It Matters

Coalitions sit at the heart of Topic 2.1 (Parliamentary, Presidential, and Semi-Presidential Systems) in [Unit 2](/ap-comp-gov/unit-2 "fv-autolink"): Political Institutions, supporting learning objective [AP Comp Gov](/ap-comp-gov "fv-autolink") 2.1.A. The whole point of distinguishing these three systems is understanding how executives get and keep power, and coalitions are the mechanism parliamentary systems use when voters don't hand any one party a majority. They also explain a big behavioral difference between systems. A UK prime minister leading a coalition can lose office the moment a partner party walks out, while Mexico's president serves a fixed six-year term no matter how hostile the legislature gets. That contrast is exactly the kind of institutional comparison the exam rewards.

## Connections

### [Coalition government (Unit 2)](/ap-comp-gov/key-terms/coalition-government)

A coalition is the alliance; a [coalition government](/ap-comp-gov/key-terms/coalition-government "fv-autolink") is the result. Once the partner parties agree to share power, the cabinet they build together, with ministries split among the parties, is the coalition government.

### [Fusion of powers (Unit 2)](/ap-comp-gov/key-terms/fusion-of-powers)

Coalitions exist because [parliamentary systems](/ap-comp-gov/key-terms/parliamentary-systems "fv-autolink") fuse the legislature and executive. Since parliament picks the prime minister, controlling a majority of seats is the only path to executive power, so parties that fall short must team up.

### [British prime minister (Unit 2)](/ap-comp-gov/key-terms/british-prime-minister)

The UK is your go-to coalition example among the six course countries. A [prime minister](/ap-comp-gov/key-terms/prime-minister "fv-autolink") without a single-party majority either builds a coalition or governs precariously, and losing coalition support can mean losing the job entirely through a vote of no confidence.

### [Cabinet (Unit 2)](/ap-comp-gov/key-terms/cabinet)

Cabinet seats are the currency of coalition bargaining. Smaller parties join coalitions in exchange for ministries, which is why coalition cabinets contain members from multiple parties, unlike Mexico's cabinet, which the president appoints without legislative consent.

## On the AP Exam

Coalitions show up most often in comparative questions about how executives gain power. The 2023 comparative analysis FRQ asked you to compare how two course countries differ in executive selection and restrictions on executive power. A coalition-dependent UK prime minister versus a fixed-term Mexican president is a strong answer skeleton for exactly that prompt. The 2017 CAQ on cabinets also opens the door to coalition reasoning, since coalition cabinets are shared across parties while presidential cabinets answer to one elected executive. Multiple-choice stems test the same contrast, like asking how forming a government in the UK differs from forming one in Mexico, or what happens in Russia's semi-presidential system when the president and parliamentary majority oppose each other. Your job is to do two things with this term. First, explain why coalitions form (no single-party majority in a parliamentary system). Second, explain the consequence (the executive depends on legislative support and can fall if the coalition collapses).

## coalition vs Coalition government

These overlap so much that they're often used interchangeably, but there's a real distinction. A coalition is the alliance of parties that together control a legislative majority. A coalition government is the executive that alliance produces, meaning the prime minister and a cabinet drawn from multiple parties. Think of the coalition as the agreement and the coalition government as the institution running the country under that agreement. On an FRQ, either term works as long as you explain the mechanism, which is that parties pooled seats because none had a majority alone.

## Key Takeaways

- A coalition forms when no single party wins a legislative majority, so multiple parties combine their seats to reach one and form a government.
- Coalitions are a parliamentary-system phenomenon because the legislature selects the head of government, so controlling a majority of seats is required to govern (PAU-3.A.1).
- Presidential systems like Mexico and Nigeria don't need coalitions to form a government, since the president is elected separately for a fixed term regardless of which party controls the legislature (PAU-3.A.2).
- Coalition partners typically receive cabinet positions in exchange for their support, so coalition cabinets include ministers from multiple parties.
- Coalition governments are less stable than single-party majority governments because a partner party leaving can cost the prime minister their legislative majority and their job.
- The UK Conservative-Liberal Democrat coalition (2010-2015) is the cleanest course-country example of a coalition in a parliamentary system.

## FAQs

### What is a coalition in AP Comparative Government?

A coalition is an alliance of two or more political parties that together hold a majority of seats in the legislature, formed so they can create a government when no single party wins a majority on its own. It's most relevant to parliamentary systems like the UK in Topic 2.1.

### Do presidential systems like Mexico need coalitions to form a government?

No. In presidential systems like Mexico and Nigeria, the executive is elected separately in a fixed-term popular election and appoints the cabinet without needing legislative approval. The president takes office and governs even if opposing parties control the legislature.

### What's the difference between a coalition and a coalition government?

A coalition is the alliance of parties pooling their legislative seats; a coalition government is the multi-party executive (prime minister plus cabinet) that alliance produces. The coalition is the deal, the coalition government is the result.

### Has the UK ever had a coalition government?

Yes. From 2010 to 2015, the Conservatives and Liberal Democrats governed together because the Conservatives won the most seats but fell short of the 326 needed for a Commons majority. It's the best course-country example to cite on an FRQ.

### Why do coalitions make governments less stable?

Because the prime minister's majority depends on every partner party staying in. If one party exits the coalition, the government can lose a vote of no confidence and fall, something a fixed-term president in Mexico or Nigeria never faces.

## Related Study Guides

- [2.1 Parliamentary, Presidential, and Semi-Presidential Systems](/ap-comp-gov/unit-2/parliamentary-presidential-semi-presidential-systems/study-guide/lHawA1movmFiqMkf2WJ0)

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