Fennel I think the structure is that -
Parliament (the elected representatives of the population) make the laws, which everyone must obey, while the courts ensure that the laws are obeyed, interpret them in the light of rulings and precedents, and deal with anyone who doesn't obey them. Ultimately, the electorate are responsible for electing MPs and forming the body of Parliament.
The cabinet is a subsection of Parliament, chaired and led by the Prime Minister. As such, it is still part of the elected body, subordinate to the decisions of the whole of Parliament, and not superior to them, although the members of the cabinet each havespecial responsibility for administering the various branches of the executive - the treasury, foreign policy etc.
These cabinet members are Ministers of the Crown, and the Prime Minister is the First Minister of the crown. He or she has been asked by the sovereign to hold that position because they appear to lead the Parliamentary group which commands enough of a majority in Parliament to expect to win votes on new laws and policies.
So the cabinet is still a part of the whole of Parliament, and subject to the decisions made by the whole of Parliament, even if they would prefer not to be. Once laws have been made by Parliament, Parliament is subject to those laws, (as is the whole population), so the Prime Minister is as subordinate to law as anyone else in the country. It is a basic tenet that no-one is above the law.
So, as I see it, the hierarchy is Courts of law, then Parliament, then the subsection of Parliament which is Cabinet Government.