However, the supremacy of Parliament means in practice the supremacy of the party or parties that has the support of Parliament on crucial issues. The Executive comprises Cabinet ministers and government departments. Cabinet is an informal body of very significant constitutional standing and real power. But Cabinet has practical limits to its power. In reaching their decisions, Cabinet members must be mindful of their colleagues in government, who are ever aware of the necessity for them to re-elected at the next election.
Parliament has the right to scrutinise the actions and finances of government departments.
Cabinet also has internal conventions to guide the way it operates. One such convention is that Ministers are collectively responsible for the decisions of government. Once a decision has been made in Cabinet, its members are meant to defend it publicly, or at least not to openly express disagreement with it. Ministers who break this convention on important matters are in theory at least expected to resign, or may be expected to be dismissed by the Prime Minister. Judges in the law courts apply the law, considering cases where the law is in dispute and deciding what the words of statutes mean when applied to particular cases.