A Government with a comfortable Commons majority can appear all-powerful. Ministers announce a policy, party managers keep their members in line, and legislation passes after a few late-night exchanges that attract little public attention. Yet parliament versus executive power is not a technical argument for constitutional specialists. It determines who tests the use of public money, who can demand an explanation for failure, and whether difficult decisions are properly examined before they become law.
Britain has never operated on a strict separation of powers. The executive is drawn from Parliament and must, in normal circumstances, retain the confidence of the House of Commons. That arrangement can produce effective government. It can also allow the Government of the day to treat Parliament as a voting machine rather than an independent institution.