Responsible Government

Responsible government is a conception of a system of government that embodies the principle of parliamentary accountability, the foundation of the Westminster system of parliamentary democracy. Governments (the equivalent of the executive branch) in Westminster democracies are responsible to parliament rather than to the monarch, or, in a colonial context, to the imperial government, and in a republican context, to the president, either in full or in part. If the parliament is bicameral, then the government is responsible first to the parliament's lower house, which is more numerous, always directly elected and thus more representative than the upper house. Responsible government of parliamentary accountability manifests itself in several ways. Ministers account to Parliament for their decisions and for the performance of their departments. This requirement to make announcements and to answer questions in Parliament means that ministers have to have the privileges of the "floor" which are only granted to those who are members of either house of Parliament. Secondly, and most importantly, although ministers are officially appointed by the authority of the head of state and can theoretically be dismissed at the pleasure of the sovereign, they concurrently retain their office subject to their holding the confidence of the lower house of Parliament. When the lower house has passed a motion of no confidence in the government, the government must immediately resign or submit itself to the electorate in a new general election.

Lastly, the head of state is in turn required to effectuate his executive power only through these responsible ministers. He or she must never attempt to set up a "shadow" government of executives or advisors and attempt to use them as instruments of government, or to rely upon their "unofficial" advice. He/she is bound to take no decision or action, which is put into effect under the color of his/her executive power, without that action being as a result of the counsel and advisement of his/her responsible ministers. His/her ministers are required to counsel him/her (i.e., explain to him/her and be sure he/she understands any issue that he/she will be called upon to decide); and, to form and have recommendations for him/her (i.e., their advice or advisement) to choose from; which are the ministers’ formal, reasoned, recommendations as to what course of action should be taken.

...
Wikipedia