Voters who remember the 1975 referendum on Europe may be feeling a touch of déjà vu as the current EU referendum speeds towards a dramatic finish this week.
We travel back in time 41 years to see how the two referendums match up.
EEC and EU: What's the difference?
In 1975, the vote was to decide whether we stayed in the European Economic Community (EEC). Back then it was essentially a free trade organisation made up of nine countries; Britain, Belgium, Denmark, France, Germany, Ireland, Italy, Luxembourg, and the Netherlands.
We had only been in it two years before a referendum was called to decide whether we should stay.
In the last 40 years, the EEC has morphed into the EU, made up of 28 European states. Some of the changes since 1975 include freedom of movement for all EU citizens, a single currency for 19 of the member states, and the induction of the European Court of Justice.
Run-up to the referendum
1975: The UK joined the EEC under a Conservative government in 1973, but in 1974 incoming Labour Prime Minister Harold Wilson called a referendum. His own party was split on the issue of EEC membership and Wilson felt a referendum would settle the matter and unite Labour.
Before the referendum, Wilson vowed to negotiate a new deal with the EEC to change the UK's role within it. After he secured this deal, he led the campaign to stay in the EEC, but gave his Cabinet colleagues free rein to choose and campaign for their allegiance.
2016: The circumstances which led to this week's referendum are strikingly similar, except now it's the Tories in power.
During the 2015 election, polls indicated that the Conservatives were losing voters to anti-EU Ukip. Under significant pressure in what many thought would be a tight election, PM David Cameron promised a referendum on the EU.
Just like Wilson, Cameron wrangled with other EU nations about a deal for Britain. He also joined the Britain Stronger In campaign, allowing his Cabinet colleagues such as Michael Gove to join Vote Leave.
1975: The economy was one of the main issues for voters to consider in making their decision, and a much more urgent issue than today.
Britain was in the midst of a double-dip recession, raising serious concerns about the UK's ability to survive outside of the EEC free-trade zone. Other issues included security of the UK's food supply and the rise of communism in Eastern Europe.
Surprisingly, immigration didn't factor much in the minds of voters. Rather, emigration of UK citizens out of the country and into EEC nations, and the skills shortage it could create, was.
2016: The economy has once again dominated the debate this time around. The value for money of EU membership is being analysed, as well as how the UK would do outside of the EU, considering the rise of other markets to trade with.
Immigration is also looming large over the debate.
As the UK economy is in better shape than in 1975, voters are considering if immigrants coming from EU countries into the UK under the principle of free movement are contributing to or subtracting from the economy.
Other issues include Britain's standing in the wider world, security against terror attacks, the migrant crisis and sovereignty.
Both in 1975 and in 2016, MPs have been given free rein to lend their support to the side of their choosing, leading to some unusual political partnerships.
In 1975 the leaders of Britain's two main parties teamed up as part of the yes to the EEC campaign, and Tony Benn and Enoch Powell both made the case for leaving the EEC.
In 2016, PM David Cameron has joined forces with leader of the opposition Jeremy Corbyn to encourage the public to stay in.
Ex-London Mayor Boris Johnson and Ukip leader Nigel Farage are campaigning on the same side to leave.
Public figures trumpeted their opinions to the public in 1975 - can you recognise any of these?
It's no different today, as a variety of business people and celebrities have lent their support to both the leave and remain campaigns.
British voters gave the EEC a strong endorsement in 1975 with 67% of the vote - and when 2016´s ballots are counted we'll find out whether the parallels with 1975 extend to the result.