Politics is a process by which groups of people make decisions
Politics definition
Politics is a process by which groups of people make decisions. The term is generally applied to behaviour within civil governments, but politics has been observed in all human group interactions, including corporate, academic, and religious institutions. It consists of "social relations involving authority or power" and refers to the regulation of a political unit, and to the methods and tactics used to formulate and apply policy. However, there is not an academic consensus on the precise definition of "politics" and what is consider as political and what is not. Max Weber defined politics as the struggle for power.
"Politics" ultimately comes from the Greek word "polis" meaning state or city. "Politikos" describes anything concerning the state or city affairs. In Latin, this was "politicus" and in French "politique". Thus it became "politics" in Middle English ( see the Concise Oxford Dictionary).
Left-right politics
Main article: Left-Right politics
Recently in history, political analysts and politicians divide politics into left wing and right wing politics, often also using the idea of center politics as a middle path of policy between the right and left. This classification is comparatively recent, and dates from the French Revolution era, when those members of the National Assembly who supported the republic, the common people and a secular society sat on the left and supporters of the monarchy, aristocratic privilege and the Church sat on the right. The meanings behind the labels have become more complicated over the years. A particularly influential event was the publication of the Communist Manifesto by Karl Marx and Frederick Engels in 1848. The Manifesto suggested a course of action for a proletarian revolution to overthrow the bourgeois society and abolish private property, in the belief that this would lead to a classless and stateless society.
Falling in line
Also, fall into line. Stick to established rules. eg, This idea falls in line with the entire agenda, or It was not easy to get all the tenants to fall into line concerning the rent hike. A related term is bring into line, meaning "to make someone fit established rules," as in It was her job to bring her class into line with the others. These terms employ line in the sense of "alignment,".

UK Politics
The politics of the United Kingdom of Great Britain and Northern Ireland has taken place in the framework of a constitutional monarchy, in which the Monarch is head of state and the Prime Minister of the United Kingdom is the head of government. Executive power is exercised by the UK government, the devolved governments of Scotland and Wales, and the Executive of Northern Ireland. Legislative power is vested in both the government and the two chambers of Parliament, the House of Commons and the House of Lords, as well as in the Scottish parliament and Welsh and Northern Ireland assemblies. The judiciary is independent of the executive and the legislature, the highest national court being the Supreme Court of the United Kingdom.
The UK is a multi-party system and since the 1920s, the two largest political parties have been the Conservative Party and the Labour Party. Though coalition and minority governments have been an occasional feature of parliamentary politics, the first-past-the-post electoral system used for general elections tends to maintain the dominance of these two parties, though each has in the past century relied upon a third party to deliver a working majority in Parliament.

Parliment
The Countries of the United Kingdom are divided into parliamentary constituencies of broadly equal population by the four Boundary Commissions. Each constituency elects a Member of Parliament (MP) to the House of Commons at General Elections and, if required, at by-elections. The number of constituencies will increase from the current 646 to 650 at the 2010 general election. Of the current 646 MPs, all but one belong to a political party. In modern times, all Prime Ministers and Leaders of the Opposition have been drawn from the Commons, not the Lords. Alec Douglas-Home resigned from his peerages days after becoming Prime Minister in 1963, and the last Prime Minister before him from the Lords left in 1902 (the Marquess of Salisbury).
One party usually has a majority in Parliament, because of the use of the First Past the Post electoral system, which has been conducive in creating the current two party system. The monarch normally asks a person commissioned to form a government simply whether it can survive in the House of Commons, something which majority governments are expected to be able to do. In exceptional circumstances the monarch asks someone to 'form a government' with a parliamentary minority which in the event of no party having a majority requires the formation of a coalition government. This option is only ever taken at a time of national emergency, such as war-time. It was given in 1916 to Andrew Bonar Law, and when he declined, to David Lloyd George and in 1940 to Winston Churchill. A government is not formed by a vote of the House of Commons, it is a commission from the monarch. The House of Commons gets its first chance to indicate confidence in the new government when it votes on the Speech from the Throne (the legislative programme proposed by the new government).