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Why Has Britain Had So Many Prime Ministers?

UK Politics — Day 3

イギリスにはなぜこれほど多くの首相がいるのか

31 July 2026

The door of 10 Downing Street under grey London sky suggesting frequent leadership change

In 2016, David Cameron stood outside 10 Downing Street and announced that he would resign. British voters had just chosen to leave the European Union, although Cameron had campaigned to remain. His departure began an extraordinary period in British politics. In the ten years following the Brexit referendum, Britain had seven prime ministers.

2016年、デーヴィッド・キャメロンはダウニング街10番地の外に立ち、辞任すると発表しました。イギリスの有権者は、キャメロンが残留を訴えていたにもかかわらず、欧州連合からの離脱を選んだばかりでした。彼の退任は、イギリス政治における異例の時期を始めました。ブレグジット国民投票後の10年間で、イギリスには7人の首相がいました。

Brexit was more than a disagreement about Britain’s relationship with Europe. It exposed deep divisions over immigration, national identity, economic policy, and Britain’s place in the world. These divisions ran through the public and the major political parties. Theresa May, Cameron’s successor, tried to negotiate a withdrawal agreement, but repeatedly failed to gain enough support in Parliament. She resigned in 2019.

ブレグジットは、イギリスとヨーロッパの関係についての意見の相違以上のものでした。移民、国家アイデンティティ、経済政策、世界におけるイギリスの位置についての深い分断を露わにしました。これらの分断は国民と主要政党の中を走っていました。キャメロンの後任であるテリーザ・メイは離脱協定の交渉を試みましたが、議会で十分な支持を得ることに繰り返し失敗しました。彼女は2019年に辞任しました。

Boris Johnson then promised to “get Brexit done.” His clear message helped the Conservatives win a large parliamentary majority in the 2019 general election, and Britain formally left the EU in 2020. However, completing Brexit did not end the political conflict surrounding it. Disagreements continued over trade, immigration, Northern Ireland, and whether Brexit had delivered the benefits its supporters had expected.

その後ボリス・ジョンソンは「ブレグジットをやり遂げる」と約束しました。彼の明確なメッセージは、保守党が2019年総選挙で大きな議会多数を得る助けとなり、イギリスは2020年に正式にEUを離脱しました。しかし、ブレグジットの完了はその周辺の政治的対立を終わらせませんでした。貿易、移民、北アイルランド、そしてブレグジットが支持者の期待した利益をもたらしたかどうかについての意見の相違は続きました。

Johnson’s personal style initially attracted voters who wanted a decisive leader. Yet his government was later damaged by scandals, including gatherings held in government buildings during COVID-19 restrictions. When ministers lost confidence in him and resigned in large numbers, Johnson was forced to step down. His fall showed how quickly a prime minister can be removed when support inside the governing party collapses.

ジョンソンの個人的スタイルは当初、決断力のある指導者を望む有権者を引きつけました。しかし彼の政権は後に、COVID-19制限中に政府建物で行われた集まりを含むスキャンダルによって傷つけられました。大臣たちが彼への信任を失い大量に辞任すると、ジョンソンは辞任を余儀なくされました。彼の失脚は、与党内の支持が崩れると首相がどれほど速く解任されうるかを示しました。

Liz Truss replaced him, but her premiership lasted only 49 days. Her government announced large tax cuts without explaining clearly how they would be funded. Financial markets reacted sharply, the pound fell, and government borrowing costs rose. Conservative MPs feared that her policies would damage both the economy and their chances of winning the next election. They replaced her with Rishi Sunak.

リズ・トラスが後任となりましたが、彼女の首相在任はわずか49日でした。彼女の政権は、どう資金を賄うかを明確に説明せずに大規模な減税を発表しました。金融市場は激しく反応し、ポンドは下落し、政府の借入コストは上昇しました。保守党下院議員たちは、彼女の政策が経済と次の選挙での勝利の可能性の両方を損なうことを恐れました。彼らは彼女をリシ・スナクに交代させました。

Sunak presented himself as a calmer and more responsible leader, but he inherited a party exhausted by years of conflict. The Conservatives also faced public anger over the cost of living, public services, immigration, and political scandals. In the 2024 general election, Labour won a large majority under Keir Starmer, ending fourteen years of Conservative government.

スナクはより冷静で責任ある指導者として自らを示しましたが、何年もの対立に疲弊した党を引き継ぎました。保守党はまた、生活費、公共サービス、移民、政治スキャンダルをめぐる国民の怒りにも直面しました。2024年総選挙で、労働党はキア・スターマーの下で大きな多数を得て、14年の保守党政権を終わらせました。

Yet Starmer’s victory did not restore long-term stability. Labour won many parliamentary seats, but its support was broad rather than deeply enthusiastic. The party soon faced dissatisfaction over economic growth, healthcare, immigration, and changes in government policy. At the same time, Reform UK challenged both Labour and the Conservatives by presenting itself as an alternative to the traditional parties. After poor election results and growing pressure from Labour MPs, Starmer stepped down in 2026 and was succeeded by Andy Burnham.

しかしスターマーの勝利は長期的な安定を取り戻しませんでした。労働党は多くの議席を得ましたが、その支持は深く熱狂的というよりも広範なものでした。党はまもなく経済成長、医療、移民、政府政策の変更をめぐる不満に直面しました。同時に、リフォームUKは伝統的な政党に代わる選択肢として自らを示し、労働党と保守党の両方に挑戦しました。悪い選挙結果と労働党下院議員からの高まる圧力の後、スターマーは2026年に辞任し、アンディ・バーナムが後任となりました。

Britain’s rapid changes of prime minister are therefore not caused by one weak leader or one unusual election. Brexit created a political fault line, scandals weakened public trust, economic shocks punished risky decisions, and Reform UK increased pressure on the traditional two-party system. Britain’s parliamentary system makes leadership change relatively easy, but the deeper cause is party politics: when MPs believe their leader can no longer unite the party or win the next election, they often look for someone new.

したがって、イギリスの急速な首相交代は、一人の弱い指導者や一つの異例の選挙によって引き起こされたものではありません。ブレグジットは政治的断層線を生み、スキャンダルは国民の信頼を弱め、経済ショックは危険な決定を罰し、リフォームUKは伝統的な二大政党制への圧力を高めました。イギリスの議院内閣制は指導者交代を比較的容易にしますが、より深い原因は党内政治です。下院議員たちが、自分たちの指導者がもはや党をまとめたり次の選挙に勝てたりできないと信じるとき、彼らはしばしば新しい人物を探すのです。

Vocabulary

  1. expose — to make a problem, weakness, or truth clearly visible. Example: The referendum exposed deep divisions within both major political parties.
  2. political fault line — a deep division in society that can cause continuing political conflict. Example: Immigration has become a major political fault line in several European countries.
  3. withdrawal agreement — an official agreement setting the conditions under which a country leaves an organization. Example: Parliament repeatedly rejected the proposed withdrawal agreement.
  4. decisive — able to make clear decisions quickly and confidently. Example: Many voters supported the candidate because he appeared to be a decisive leader.
  5. collapse — to fail suddenly or lose strength and support. Example: The prime minister resigned after support for her government collapsed.
  6. inherit — to receive a situation, responsibility, or problem from the person who held a position before. Example: The new leader inherited serious economic and political problems.
  7. broad but shallow — supported by many people, but without strong or lasting enthusiasm. Example: The party’s election victory was based on support that later appeared broad but shallow.
  8. traditional two-party system — a political situation in which two major parties usually dominate elections and government. Example: Smaller parties are placing increasing pressure on Britain’s traditional two-party system.
  9. unite — to bring people together so that they support the same purpose or leader. Example: The new prime minister must try to unite a deeply divided party.

Comprehension Questions

  1. Why did David Cameron resign in 2016?
    1. His party lost a general election.
    2. Voters rejected his position in the Brexit referendum.
    3. Parliament removed him over an economic crisis.
    4. He joined another political party.

    デーヴィッド・キャメロンが2016年に辞任したのはなぜですか？

  2. Why was Theresa May unable to remain prime minister?
    1. She refused to negotiate with the European Union.
    2. She lost her seat in a by-election.
    3. She could not gain enough parliamentary support for her Brexit agreement.
    4. She wanted Britain to rejoin the European Union.

    テリーザ・メイが首相のままでいられなかったのはなぜですか？

  3. What contributed to Boris Johnson’s resignation?
    1. A collapse of support among government ministers and Conservative MPs
    2. A direct national vote to remove him
    3. His opposition to Brexit
    4. Reform UK winning a parliamentary majority

    ボリス・ジョンソンの辞任に寄与したのは何ですか？

  4. Why did Liz Truss remain prime minister for only 49 days?
    1. Her economic plan caused a strong negative reaction in financial markets.
    2. She lost a referendum on immigration.
    3. She refused to lower taxes.
    4. Labour MPs selected a new Conservative leader.

    リズ・トラスが首相をわずか49日しか務めなかったのはなぜですか？

  5. What broader explanation does the article give for Britain’s frequent leadership changes?
    1. British voters directly replace the prime minister every year.
    2. The monarch regularly removes unpopular leaders.
    3. Political divisions, scandals, economic pressures, and internal party fears have weakened leaders.
    4. Britain no longer holds general elections.

    記事はイギリスの頻繁な指導者交代についてどのようなより広い説明をしていますか？

Discussion Questions

  1. Was Brexit the main cause of Britain’s political instability, or did it simply reveal problems that already existed?

    ブレグジットはイギリスの政治的不安定の主な原因でしたか、それともすでに存在していた問題を単に露わにしましたか？

  2. Should MPs be able to remove a prime minister who recently won a general election?

    下院議員は、最近総選挙に勝った首相を解任できるべきですか？

  3. Why might political parties replace their leaders instead of changing their policies?

    政党が政策を変える代わりに指導者を交代させることがあるのはなぜですか？

  4. Does the growth of Reform UK make British politics more democratic or more unstable?

    リフォームUKの成長は、イギリス政治をより民主的にしますか、それともより不安定にしますか？

  5. What matters more to voters: a leader’s policies, personality, or ability to unite a party?

    有権者にとってより重要なのは何ですか―指導者の政策、人柄、それとも党をまとめる能力ですか？

Speaking Task

  1. Explain why Britain has had so many prime ministers since the Brexit referendum. Include: how Brexit divided British politics; what happened to Boris Johnson and Liz Truss; why Labour later replaced Keir Starmer; the growing influence of Reform UK; and the role of internal party politics. Speak for about one minute.

    ブレグジット国民投票以降、イギリスにこれほど多くの首相がいた理由を説明してください。ブレグジットがイギリス政治をどう分断したか、ボリス・ジョンソンとリズ・トラスに何が起きたか、労働党がその後キア・スターマーを交代させた理由、リフォームUKの影響力の増大、党内政治の役割を含めてください。約1分間話してください。