Modern British government is government by party leaders in Cabinet. It is still the “Crown in Parliament” which formally takes or authorizes every legislative or administrative action, but of the three major components of this composite entity – the Commons, the Lords, and the Sovereign – the first is now virtually unchecked. The House of Lords can only minimally delay acts of the elected assembly, and both the Lords and the Monarch have long since lost their ability to veto (much less initiate) legislation. Since the Cabinet controls the agenda of the House of Commons and generally consists solely of the leaders of the party with a majority of seats in the Commons, and since the influence of party on voting in Parliament is extremely strong, the Commons itself has in essence retained only a veto and, to a lesser extent, an amendment power over the legislative proposals of the majority party's leaders who sit in the Cabinet. As a recent essay on legislation in Britain notes, today's conventional wisdom is that “parliament has relinquished any capacity for legislative initiative it may once have possessed to the executive in its midst” (Walkland and Ryle 1981: 91).

Corresponding to this widely accepted view of a party-dominated legislative process is a conception of parliamentary elections as essentially methods of choosing which party shall rule. Electoral organization is dominated by the parties rather than by individual candidates, and it is for parties rather than individuals that British voters are generally thought to vote. Representation in modern Britain is conceived of as almost exclusively “national” and party-based.