The Executive Government consists of the Cabinet and the Ministry led by the Prime Minister. The Ministry is derived from the party (or parties) that command the confidence of the legislature.
The Ministry consists of all those Members of Parliament chosen by the Prime Minister (or in some countries, the party caucus). They serve as members of the executive arm of government and administer the various government departments.
There is often confusion between the ministry and the cabinet. In some countries, there is a clear distinction between the ministry and cabinet. In these instances, only the most senior Ministers, including the Prime Minister, form the Cabinet. So while all Cabinet Ministers are members of the ministry, not all members of the ministry are members of the Cabinet.
Other countries don’t observe this distinction, or if they do, the distinction between the two is much less clear.
In the UK, the number of paid ministerial posts is set out in the Ministerial and Other Salaries Act, 1975. This Act limits the size of paid cabinet positions to 22 (21 MPs and one peer). The ministry, however, is much larger. The same Act limits the ministry to 109 paid appointments. If the maximum number of Cabinet Ministers are appointed, a maximum of 29 Ministers of State and 33 paid Parliamentary Secretaries may be appointed. Of course, the Prime Minister can have an even larger ministry – the Act only limits how many ministers can be paid appointments, that is, MPs who will receive additional remuneration above the base salary of an MPs. There is no limit on the number of non-paid appointments.
Another interesting note is that the House of Commons Disqualifications Act, 1975, limits the number of ministers who can be in the House of Commons at one time to 95. This limit does not depend on whether or not the office holders are paid. You can see the current list of UK ministers (Cabinet and department ministers) here. The list starts with the Cabinet, followed by the nine ministers who also attend Cabinet, but aren’t Cabinet ministers, then the list of all ministers by department, including Ministers of State and Parliamentary Under Secretaries of State.
Some MPs in the UK are also appointed Parliamentary Private Secretaries (PPSs). They do not receive any additional remuneration for this, however, and are not considered to be part of the ministry.
In Canada, the division between the ministry and Cabinet doesn’t exist. As you can see on the official Ministry page, there is no distinction between Cabinet ministers and other ministers – all members of the ministry are part of the Cabinet. There is also no legislation limiting the number of Cabinet and other ministers as there exists in the UK. The current Canadian Cabinet totals 39 ministers.
As in the UK, the Prime Minister can also appointment a number of parliamentary secretaries. Yet unlike PPSs in the UK, parliamentary secretaries in Canada do receive additional remuneration above the base pay for an MP. However, they are not part of the Ministry. When Paul Martin became prime minister in December 2003, he appointed parliamentary secretaries to the Privy Council and said they would be invited to cabinet meetings when a policy matter for which they had specific duties was to be discussed. The current Prime Minister has returned to the earlier practice of not appointing parliamentary secretaries to the Privy Council. Under the Parliament of Canada Act, the number of parliamentary secretaries may not exceed the number of ministers.
Australia distinguishes between Cabinet and the Ministry. There are 20 Cabinet Ministers (including the PM), but a total of 30 ministers (an additional 10 ministers do not attend cabinet), and 12 parliamentary secretaries. All Ministers and Parliamentary Secretaries become members of the Executive Council. They receive the title “Honourable”. The Council’s full membership never meets. In practice the minimum number of Ministers or Parliamentary Secretaries (that is, two in addition to the person presiding) are rostered to attend. Meetings of the Council are presided over by the Governor-General or a deputy appointed by the Governor-General (usually the Minister with the title Vice President of the Executive Council). The matters dealt with at each meeting are recommendations by Ministers, for the approval of the Governor-General in Council, that something be done—for example, that a regulation be made, a treaty be ratified, or a person be appointed to a position.
While the Executive Council may seem no more than a rubber stamp, the processes involved in bringing matters before the Council ensure that Ministers’ actions are properly documented, are legally and constitutionally valid, and are in accordance with government policy.
New Zealand also has 20 Cabinet Ministers, plus five Ministers outside Cabinet who may attend Cabinet if needed, and three support party Ministers (link). Support party ministers are from the parties with support and confidence agreements with the governing National Party. New Zealand also has Parliamentary under-secretaries who are government MPs who are appointed to assist ministers with their portfolio duties. They do not have the powers of ministers, and are not members of the Executive Council. All ministers are members of the Executive Council, whether or not they are members of cabinet. The Executive Council is the highest formal institution of government in New Zealand, and is the means by which the government provides collective and formal advice to the governor general. The Executive Council generally meets weekly, following the meeting of cabinet, and is presided over by the governor general. The Executive Council implements decisions that require the force of law through regulations made by orders in council. It is the legislative executive, while cabinet is the political executive.