European Communities Act 1972 (UK) in the context of "European Atomic Energy Community"

The European Union (Withdrawal) Act 2018 (c. 16) is an act of the Parliament of the United Kingdom to repeal the European Communities Act 1972, and for parliamentary approval to be required for any withdrawal agreement negotiated between the Government of the United Kingdom and the European Union. Initially proposed as the Great Repeal Bill, its passage through both Houses of Parliament was completed on 20 June 2018 and it became law by Royal Assent on 26 June.

The act is to enable "cutting off the source of EU law in the UK ... and remove the competence of EU institutions to legislate for the UK". The 2017–2019 Government of Theresa May regarded it as the most significant constitutional legislation to have been passed by Parliament since the European Communities Act itself in 1972.

The Scotland Act 1998 (c. 46) is an Act of the Parliament of the United Kingdom which legislated for the establishment of the devolved Scottish Parliament with tax varying powers and the Scottish Government (then Scottish Executive). It was one of the most significant constitutional pieces of legislation to be passed by the UK Parliament between the passing of the European Communities Act in 1972 and the European Union (Withdrawal) Act in 2018 and is the most significant piece of legislation to affect Scotland since the Acts of Union in 1707 which ratified the Treaty of Union and led to the disbandment of the Parliament of Scotland.