How Confidence-and-Supply Agreements Keep Minority Governments in Power

On June 26, 2017, inside the Cabinet Room at 10 Downing Street, Democratic Unionist Party leader Arlene Foster and UK Prime Minister Theresa May signed a three-page document. That signature kept the Conservative party in power without granting the DUP a single ministerial portfolio.[1]

The arrangement was a confidence-and-supply agreement, a constitutional mechanism that allows a minority party to govern. It trades guaranteed votes on existential parliamentary motions for targeted policy concessions, keeping the state functioning without a formal coalition.

Unlike a formal coalition, the supporting party remains on the opposition benches. They do not attend cabinet meetings, they do not defend government policy, and they retain the right to vote against the government on routine legislation.

This structure defines modern minority parliaments across the Westminster system. From Ottawa to Wellington, confidence-and-supply agreements offer a pragmatic middle ground between immediate electoral collapse and the deep ideological compromise required to form a shared executive.[2]

The mechanics of minority survival

In a Westminster democracy, a government only exists as long as it commands the confidence of the elected chamber. If a prime minister loses a vote of no confidence, the government falls, triggering either a new administration or a general election.

"Confidence" refers strictly to these existential tests, including the speech from the throne or explicit censure motions. "Supply" refers to the passage of budget bills required to fund the state apparatus and pay public sector workers.

A confidence-and-supply agreement guarantees that the junior party will vote with the government on both of these metrics. In exchange, the governing party agrees to pass specific legislation favored by the junior partner and consult them on major decisions.[1]

The 2017 UK agreement, for example, secured £1 billion in additional funding for Northern Ireland over two years. The DUP delivered their ten votes on budgets and Brexit legislation, but remained free to oppose the Conservatives on domestic English policies.[1]

The cabinet barrier

The defining difference between this arrangement and a formal coalition is the composition of the executive. In a coalition, multiple parties share cabinet seats and are bound by the strict constitutional convention of collective ministerial responsibility.[2]

Collective responsibility dictates that all ministers must publicly support government decisions, regardless of their party's internal platform. A junior coalition partner must defend policies they campaigned against if the cabinet adopts them, risking severe backlash from their core voters.

Confidence-and-supply agreements bypass this trap entirely. Because the supporting party holds no cabinet positions, they are not bound by collective responsibility and can publicly criticize the very government they are keeping in power through their budget votes.

"The junior party gets to act as both kingmaker and critic," notes a 2023 structural review by the Institute for Government. "They extract the policy wins of a governing party while maintaining the purity of an opposition faction."

This distance is particularly valuable when the governing party is unpopular. The supporting party can distance itself from executive scandals or economic downturns, arguing they are merely providing national stability, not endorsing the administration's broader agenda.

Pricing the legislative vote

The cost of a confidence-and-supply agreement is negotiated explicitly, often resulting in a published memorandum of understanding. These documents outline exactly which bills the junior party will support and what financial or legislative commitments they receive in return.[2]

In Canada, the March 2022 agreement between the governing Liberals and the opposition New Democratic Party was priced in social programs. The NDP guaranteed confidence votes until June 2025 in exchange for a national dental care program.

The Canadian pact required the government to launch dental coverage for children under 12 by the end of 2022, expanding to all low-income households by 2025. The NDP retained the right to collapse the government if these specific deadlines were missed.

These agreements rarely cover foreign policy or defense unless explicitly stated in the text. The supporting party typically abstains or votes its conscience on international deployments, forcing the minority government to seek votes from other opposition parties to pass military authorizations.[1]

When the UK Parliament voted on military action in Syria in 2013, the minority government could not rely on a blanket agreement. They lost the vote 285 to 272, demonstrating the limits of informal parliamentary pacts when dealing with unscripted crises.[1]

The enforcement of these agreements relies entirely on political leverage rather than legal binding. If a prime minister reneges on a promised policy, the junior party cannot sue in court; their only recourse is to vote down the next budget and trigger an election.[3]

This creates a continuous cycle of brinkmanship throughout the parliamentary term. Every major fiscal event becomes a renewed negotiation, with the junior party threatening to withhold supply unless further concessions are added to the original memorandum of understanding.[3]

The timeline of collapse

Despite the written guarantees, confidence-and-supply agreements are inherently less stable than formal coalitions. A comparative analysis of Westminster parliaments since 1996 reveals a stark difference in government longevity when the executive is not shared.[3]

Minority governments sustained by confidence-and-supply agreements collapse, on average, 14 months earlier than formal multi-party coalitions. The lack of shared executive power removes the primary structural incentive for the junior party to maintain the arrangement during difficult polling periods.[3]

In a coalition, collapsing the government means junior ministers lose their salaries, their departments, and their executive authority. In a confidence-and-supply arrangement, the junior party loses nothing but a negotiating partner, making the trigger much easier to pull.[3]

This dynamic makes the agreements highly sensitive to public polling. If the supporting party sees a surge in their electoral popularity, they have a strong incentive to manufacture a crisis over a supply bill and force an early election to maximize their seat count.

Conversely, if the governing party surges in the polls, the prime minister may dissolve parliament early to seek a majority. The 2020 New Zealand election saw the Labour party abandon its previous agreements after securing 65 of 120 seats outright.[2]

The ballot box penalty

Electoral history suggests that junior partners in both coalitions and confidence-and-supply agreements suffer at the ballot box. Voters frequently credit the governing party for popular policies while blaming the supporting party for any compromises made to keep the government alive.

Following the 2010-2015 UK Conservative-Liberal Democrat formal coalition, the junior Liberal Democrats lost 49 of their 57 parliamentary seats. The electorate punished them severely for abandoning their core pledge on university tuition fees in order to maintain cabinet solidarity.[1]

Parties utilizing confidence-and-supply agreements attempt to avoid this fate by remaining in opposition. However, historical data from the Canadian Parliament shows that junior partners still lose an average of 12% of their vote share in the subsequent general election.

"Voters struggle to distinguish between a party that governs and a party that merely enables the government," writes political scientist Jonathan Malloy. "The nuance of confidence motions is lost on a public angry about inflation or housing costs."

To counter this, supporting parties often adopt aggressive rhetoric against the government they sustain. They must constantly prove to their base that they are extracting maximum value for their votes while remaining ideologically distinct from the prime minister.

The future of minority rule

As traditional two-party systems fragment across Western democracies, minority governments are becoming the statistical norm rather than the exception. Proportional representation systems inherently produce parliaments where no single party holds a majority of the seats.[2][3]

In these fragmented environments, the confidence-and-supply agreement serves as the primary constitutional tool for state function. It allows ideologically opposed parties to pass national budgets without forcing them into the unnatural embrace of a shared cabinet.[3]

The mechanism ensures that the state can collect taxes, fund essential public services, and pass emergency legislation, even when the fractured electorate refuses to grant any single political faction a clear mandate to govern alone.

The survival of these agreements depends entirely on mutual weakness. As long as both the governing party and the supporting party fear the outcome of an immediate election, the supply bills will continue to pass and the government will stand.[3]