Supermajorities have been used for centuries, both in parliaments and referendums.
Historically the UK doesn’t use referendums and there are 2 kinds – ones that are binding on the government and those that aren’t
1 January 1973 The United Kingdom, the Republic of Ireland and Denmark entered the 'European Economic Community (EEC),
Then United Kingdom European Communities membership referendum was a public vote that took place on 5 June 1975,
In that referendum in 1975 the UK electorate voted to stay in the EEC. The electorate voted ‘Yes' by 67.2% to 32.8% to stay in Europe. – a super majority.This was the first national referendum ever to be held throughout the United Kingdom, and would remain the only UK-wide referendum until the 2011
Many countries require supermajorities either in parliament or in a referendum to make major changes - These Acts/referendums especially constitutional ones require what is commonly referred to as a “Super-majority”
The first known use of a supermajority rule was over 2000 years ago in in ancient Rome.
The catholic church has used them since the 12th century.
The following countries/treaties require supermajorities, mostly in reference to constitutional change – note also that many use their parliament as opposed to a referendum – as they are not necessarily considered to be that democratic
The Council of the European Union uses 'Qualified majority voting' for the majority of issues brought before the institution. However, for matters of extreme importance for individual member states, unanimous voting is implemented. An example of this is Article 7 of the Treaty on European Union, whereby a member state
Australia - To pass an amendment to the Australian Constitution, a referendum is required and must achieve a "double majority":
Canada - for most constitutional amendments
Denmark - if the government or parliament wants to cede parts of national sovereignty to an international body such as the European Union or the United Nations, it has to get a five-sixths majority
Indian Constitution requires a supermajority of two-thirds of members present and voting in each house
Finland - when a new legislative proposal would in some way add, alter or remove a part of the Finnish constitution, a bill requires a 2/3 majority
Japan.
New Zealand
Nigeria
Philippines
Singapore
South Korea
Spain
Taiwan
Turkey
Ukraine
United Kingdom
United States
United Nations - requires a supermajority of the fixed membership on substantive matters