Scotland, Wales and Northern Ireland have devolved legislatures and executives, while England does not. The authority of these devolved legislatures is dependent on Acts of Parliament and, although it is politically very unlikely, they can in principle be abolished at the will of the Parliament of the United Kingdom.    However, the acts that created the devolved institutions are considered constitutional statutes that are not subject to implied repeal.  Constitional law professors have described this as a transfer "real power" that alters the sovereignty of the UK Parliament to a "supervisory" role over the devolved legislatures in regard of devolved matters.  Furthermore, the Scotland Act 2016 expresses the constitutional intent that the Scottish Parliament and Scottish Government are permanent and declares that they are not to be abolished except following a referendum in Scotland.   A historical example of a legislature that was created by Act of Parliament and later abolished is the Parliament of Northern Ireland , which was set up by the Government of Ireland Act 1920 and abolished, in response to political violence in Northern Ireland, by the Northern Ireland Constitution Act 1973 (Northern Ireland has since been given another legislative assembly under the Northern Ireland Act 1998 ). The Greater London Council was abolished in 1986 by the Local Government Act 1985  and a similar institution, the Greater London Authority , was established in 2000 by the Greater London Authority Act 1999 .