This essay shall focus on how the parliament of UK can repeal the EU Communities Act 1972 or art 501. Commencing with the state of United Kingdom, the UK government is a parliamentary democracy of a constitutional monarchy. The power of the state has been divided amongst three branches namely- the parliament, the judiciary and the executive. On the contrary, there has always been a controversy between the separation of power in the United Kingdom. There is somewhat overlap of power between the branches of the state. It can, therefore, be concluded that the citizens and parliament through the constitution can enforce or repeal the European Communities Act 1972 or Article 50.