The Government is led by the Prime Minister, who chooses the other Ministers. The Prime Minister and the other most powerful Ministers belong to a group known as the Cabinet, who are the most important decision makers in the Government. These ministers are all members of Parliament (MPs). Laws are made by MPs voting in Parliament, which is called 'legislative authority'. These laws make what is called primary legislation.
The government is chosen by the people indirectly. The people of the United Kingdom vote in a general election, appointing representatives to the Parliament, at least once every five years. The monarch must select as Prime Minister the person who is likely to have the support of Parliament. By convention, that is normally the leader of the party that has the most MPs in the House of Commons. The Prime Minister leads the government and exercises executive power on behalf of the monarch, in accordance with the laws set by Parliament, including appointing Ministers to the executive branches of government. 
Under the British constitution, laws are made or unmade by Parliament, the power to "give assent" to the laws belongs to the monarch. The policy and administration of the laws is done by the direction of the Prime Minister and the Cabinet. This is called executive authority. The monarch is obliged to follow the advice of the government and has not refused to do so since the 17th century. The Cabinet members advise the monarch as part of a group called Privy Council. They also use their power directly as leaders of the Government departments.
There are separate governments in Wales, Scotland and Northern Ireland, each responsible to their own local parliament. These parliaments have certain limits decided by the main parliament in Westminster. There is no separate English Parliament.
- Her Majesty's Government Parliament of the United Kingdom, 28 June 2010
- Overview of the UK system of government : Directgov – Government, citizens and rights. Direct.gov.uk. Retrieved on 2010-10-19.
- General elections – UK Parliament. Parliament.uk (2010-05-06). Retrieved on 2010-10-19.
- House of Commons – Justice Committee – Written Evidence. Publications.parliament.uk. Retrieved on 2010-10-19.
- "Parliament and government". UK Parliament. Retrieved 2019-06-25.
- The monarchy : Directgov – Government, citizens and rights. Direct.gov.uk. Retrieved on 2010-10-19.
- House of Lords Record Office. "The making and keeping of Acts at Westminster" (PDF).
- Jones, Clyve 2012. A short history of Parliament: England, Great Britain, the United Kingdom, Ireland and Scotland, p. 1; excerpt, "It is a commonly held misconception that the Westminster parliament is the 'mother of all parliaments' ... but the original phrase in 1865 was 'England is the mother or all parliaments'".