Politics of the United Kingdom
The UK Parliament is the supreme legislative body in the United Kingdom (i.e., there is parliamentary sovereignty), and Government is drawn from and answerable to it. Parliament is bicameral, consisting of the House of Commons and the House of Lords. There is also a devolved Scottish Parliament and devolved Assemblies in Wales and Northern Ireland, with varying degrees of legislative authority.
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 representative than the upper house, as it has more members and they are always directly elected.