The concept of the separation of powers has been applied to the United Kingdom and the nature of its executive (UK government, Scottish Government, Welsh Government and Northern Ireland Executive), judicial (England and Wales, Scotland and Northern Ireland) and legislative (UK Parliament, Scottish Parliament, National Assembly for Wales and Northern Ireland Assembly) functions. Historically, the apparent merger of the executive and the legislature, with a powerful Prime Minister drawn from the largest party in parliament and usually with a safe majority, led theorists to contend that the separation of powers is not applicable to the United Kingdom. However, in recent years it does seem to have been adopted as a necessary part of the UK constitution.