Downing Street in London, England has for over two hundred years housed the official residences of two of the most senior British cabinet ministers: the First Lord of the Treasury, an office now synonymous with that of Prime Minister of the United Kingdom, and the Second Lord of the Treasury, an office held by the Chancellor of the Exchequer. The Prime Minister's official residence is 10 Downing Street; the Chancellor's official residence is next door at Number 11. The Government's Chief Whip has an official residence at Number 9.

Downing Street is located in Whitehall in central London, a few minutes' walk from the Houses of Parliament and a little farther from Buckingham Palace. The street was built in the 1680s by Sir George Downing (1632–1689) on the site of a mansion called Hampden House. The houses on the west side of the street were demolished in the nineteenth century to make way for government offices, now occupied by the Foreign and Commonwealth Office.

David William Donald Cameron (pronunciation: /ˈkæmərən/; born 9 October 1966) is the Prime Minister of the United Kingdom, First Lord of the Treasury, Minister for the Civil Service and Leader of the Conservative Party. He represents Witney as its Member of Parliament (MP).

Cameron studied Philosophy, Politics and Economics (PPE) at Oxford, gaining a first class honours degree. He then joined the Conservative Research Department and became Special Adviser to Norman Lamont, and then to Michael Howard. He was Director of Corporate Affairs at Carlton Communications for seven years.

He was defeated in his first candidacy for Parliament at Stafford in 1997, but was elected in 2001 as the Member of Parliament for the Oxfordshire constituency of Witney. He was promoted to the Opposition front bench two years later, and rose rapidly to become head of policy co-ordination during the 2005 general election campaign. With a public image of a youthful, moderate candidate who would appeal to young voters, he won the Conservative leadership election in 2005.

Margaret Hilda Thatcher, Baroness Thatcher, LG, OM, PC, FRS, née Roberts (born 13 October 1925) is a British politician and the longest-serving (1979–1990) British prime minister of the 20th century, and the only woman ever to have held the post. A Soviet journalist nicknamed her the "Iron Lady", which later became associated with her uncompromising politics and leadership style. As prime minister, she implemented conservative policies that have come to be known as Thatcherism.

Originally a research chemist before becoming a barrister, Thatcher was elected Member of Parliament (MP) for Finchley in 1959. Edward Heath appointed her Secretary of State for Education and Science in his 1970 government. In 1975 Thatcher defeated Heath in the Conservative Party leadership election and became Leader of the Opposition, as well as the first woman to lead a major political party in the United Kingdom. She became prime minister after winning the 1979 general election.

After entering 10 Downing Street, Thatcher introduced a series of political and economic initiatives to reverse what she perceived as Britain's precipitous national decline. Her political philosophy and economic policies emphasised deregulation (particularly of the financial sector), flexible labour markets, the privatisation of state-owned companies, and reducing the power and influence of trade unions. Thatcher's popularity during her first years in office waned amid recession and high unemployment, until economic recovery and the 1982 Falklands War brought a resurgence of support, resulting in her re-election in 1983. Thatcher was re-elected for a third term in 1987, but her Community Charge (popularly referred to as "poll tax") was widely unpopular and her views on the European Community were not shared by others in her Cabinet. She resigned as Prime Minister and party leader in November 1990, after Michael Heseltine launched a challenge to her leadership.