Official Opposition frontbench in the context of "His Majesty's Most Loyal Opposition"

The Government frontbench in the Parliament of the United Kingdom, also known as the Treasury Bench, consists of the Cabinet and all other ministers.

Parliamentary opposition to the Government frontbench is provided by the Official Opposition frontbench and the Liberal Democrat frontbench team.

The shadow cabinet or shadow ministry is a feature of the Westminster system of government. It consists of a senior group of opposition spokespeople who, under the leadership of the Leader of the Opposition, form an alternative cabinet to that of the government, and whose members shadow or mirror the positions of each individual member of the Cabinet. Their areas of responsibility, in parallel with the ruling party's ministries, may be referred to as a shadow portfolio. Members of a shadow cabinet have no executive power. It is the shadow cabinet's responsibility to scrutinise the policies and actions of the government, as well as to offer alternative policies. The shadow cabinet makes up the majority of the Official Opposition frontbench, as part of frontbenchers to the parliament. Smaller opposition parties in Britain and Ireland have Frontbench Teams.

In many countries, a member of the shadow cabinet is referred to as a shadow minister. In the United Kingdom's House of Lords and in New Zealand, the term spokesperson is used instead of shadow. In Canada, the term opposition critic is also used.

The shadow chancellor of the exchequer in the British Parliamentary system is the member of the Shadow Cabinet who is responsible for shadowing the chancellor of the exchequer. The title is given at the gift of the leader of the Opposition and has no formal constitutional role, but is generally considered the second-most senior position, unless a shadow deputy prime minister is chosen, on the opposition frontbench, after the leader. Past shadow chancellors include Harold Wilson, James Callaghan, Edward Heath, Geoffrey Howe, Kenneth Clarke, Gordon Brown, John McDonnell and Rachel Reeves.

The name for the position has a mixed history. It is used to designate the lead economic spokesman for the Opposition. The name 'Shadow Chancellor' has also been used for the corresponding position for the Liberal Democrats, the Liberal Democrat Treasury spokesperson. This was a source of humour for Chancellor Gordon Brown, who in 2005 played the two off against one another in Parliament, saying, "I, too, have a great deal of time for the shadow chancellor who resides in Twickenham [Liberal Democrat Vince Cable], rather than the shadow chancellor for the Conservative Party."