Britain's referendum on whether to remain in the EU has taken place in a climate of growing euroscepticism across the bloc, and is just the latest of many EU plebiscites.

National referendums over the past 44 years have often determined the direction taken by the EU, whether by admitting new members, expanding its powers via treaty changes, or embarking on new projects.

Norway stays out
Norwegians voted to stay out of the expanding European Economic Community in September 1972 and again in November 1994 when Austria, Finland and Sweden joined what has since become the EU. Norway is the only country to have decided at a referendum not to join.

No Brexit in 1975
Britain did not hold a referendum on whether to join the EEC in 1973, but the Labour government of Harold Wilson organised a popular vote in 1975 in which voters decided to stay in by 67.2 percent.

The Euro and treaty changes
The Maastricht Treaty, laying the groundwork for the European Union and for European monetary union, did not go smoothly.

On June 2, 1992, Danes surprised European neighbours when they turned down the treaty by 50.7 percent.

They backed an amended version by a narrow margin in May 1993, but only after Denmark had secured greater autonomy in defence, currency, citizenship matters and judicial cooperation.

A slight majority of French voters, 51.05 percent, approved the treaty in a referendum held on September 20, 1992.

Two countries held referendums on joining the euro, which was created in 1999.

In September 2000, just over 53 percent of Danes rejected the single currency, and in September 2003, neighbouring Sweden found that 56.1 percent of voters wanted to keep their krona.

French and Dutch block the European Constitution
When asked to approve the European Constitution in May 2005, almost 55 percent of French voters said "No" and more than 61 percent of the Dutch rejected the draft three days later.

Ireland says 'No' then 'Yes'
The Treaty of Nice contained key institutional reforms needed for the bloc's eastwards enlargement in 2004.

It only faced a referendum in Ireland where it was initially rejected by 54 percent in June 2001 as supporters underestimated local opposition.

After obtaining guarantees regarding Ireland's cherished military neutrality, a second referendum was approved by 62.9 percent on October 19, 2002.

It was the same story with the Treaty of Lisbon, negotiated to partly replace the stalled constitution: on June 12, 2008 Ireland said "No", but approved it with a second vote in October 2009.

Ukraine
In early April 61 percent of Dutch voters rejected a key European pact with Ukraine in a non-binding referendum seen as a barometer of anti-EU feeling.