1. Margaret Thatcher (1979-1990)

• Controversies: Thatcher's tenure was marked by a number of controversial policies, including the implementation of strict monetarist economic policies, the privatisation of state-owned industries, and the weakening of trade unions. Her handling of the miners' strike in 1984-85, the introduction of the highly unpopular "poll tax," and her stance on apartheid in South Africa also attracted significant criticism.

2. Tony Blair (1997-2007)

• Controversies: Blair's decision to support the U.S. invasion of Iraq in 2003 based on the disputed claim that Saddam Hussein possessed weapons of mass destruction remains one of the most controversial aspects of his leadership. His close relationship with U.S. President George W. Bush and the resulting military actions have been widely condemned.

3. David Cameron (2010-2016)

• Controversies: Cameron is perhaps most controversial for his decision to hold the 2016 EU referendum, which resulted in Brexit. Critics argue that he misjudged the public sentiment and failed to anticipate the political and economic fallout. His austerity policies, including cuts to public services, also faced significant backlash.

4. Theresa May (2016-2019)

• Controversies: May's tenure was dominated by her handling of Brexit, particularly her inability to secure a deal that could pass through Parliament, leading to political gridlock and the eventual extension of Brexit deadlines. Her "hostile environment" immigration policy, which led to the Windrush scandal, also attracted criticism.

5. Boris Johnson (2019-2022)

• Controversies: Johnson's leadership saw the UK finally exit the EU, but his handling of the COVID-19 pandemic, including accusations of government mismanagement and the "Partygate" scandal (where he and others were found to have breached lockdown rules), led to significant controversy. His government's ethics and his personal conduct were frequently called into question.

6. Winston Churchill (1940-1945, 1951-1955)

• Controversies: Although Churchill is widely celebrated for his leadership during WWII, his legacy is not without controversy. His role in the Bengal famine of 1943, his views on race and empire, and his actions during the Mau Mau uprising in Kenya have led to criticism of his leadership and policies.

7. Harold Wilson (1964-1970, 1974-1976)

• Controversies: Wilson's governments were marked by economic difficulties, including inflation and devaluation of the pound. His handling of the Rhodesia crisis, allegations of improper conduct with the trade unions, and accusations of MI5 surveillance against him were sources of controversy.

8. Edward Heath (1970-1974)

• Controversies: Heath's decision to take the UK into the European Economic Community (EEC) was highly divisive, with critics arguing that it compromised British sovereignty. His handling of the miners' strikes, leading to the three-day week, and the Troubles in Northern Ireland also sparked controversy.

9. John Major (1990-1997)

• Controversies: Major's government was plagued by a series of scandals, including the "cash for questions" affair, where MPs were accused of accepting money in exchange for raising issues in Parliament. His leadership during the early 1990s recession and his handling of the Black Wednesday financial crisis also drew criticism.

10. Gordon Brown (2007-2010)

• Controversies: Brown's time in office was dominated by the global financial crisis of 2007-2008. While he was credited with taking decisive action to stabilise the UK economy, his handling of the crisis, including the controversial bank bailouts and subsequent austerity measures, was heavily debated. His leadership style was often criticised as being indecisive and lacking in charisma.