The United Kingdom (UK) famously voted to leave the European Union in 2015 with a surprise leave vote (Brexit). It was legally set in motion in 2019 by Conservative prime minister Boris Johnson:
Brexit (/ˈbrɛksɪt, ˈbrɛɡzɪt/; a portmanteau of "British" and "exit") is the withdrawal of the United Kingdom (UK) from the European Union (EU). Following a UK-wide referendum in June 2016, in which 52% voted to leave and 48% voted to remain in the EU, the UK Government which was then led by Theresa May formally declared the country's withdrawal on 29 March 2017, beginning the Brexit process. The withdrawal was originally scheduled for 29 March 2019 but was then delayed by deadlock in the UK Parliament after the June 2017 general election resulted in an unexpected hung parliament, which then led to three subsequent extensions of the Article 50 process. The deadlock was only resolved after a subsequent general election was held in December 2019. Following the outcome, the UK Parliament finally ratified the withdrawal agreement, and the UK left the EU at 11 p.m. GMT on 31 January 2020. This began a transition period that is set to end on 31 December 2020, during which the UK and EU are negotiating their future relationship. The UK remains subject to EU law and remains part of the EU customs union and single market during the transition, but is no longer part of the EU's political bodies or institutions.
However, there seems to be nothing preventing a new government from having the UK rejoin the union. In fact, various people have written on this already, even predicting it will happen in "a decade's time". The question is: Will the UK rejoin the European Union before 2030?
Resolves positively if the future UK government and parliament legally rejoins the union.
If the EU ceases to exist before resolution, this question resolves negatively
If the EU changes its name or function, and the UK rejoins this new body, the question resolves positively