It's '#EuropeDay' but is the tide turing on the 'ever-closer Union'?
Almost half of voters in eight large European Union countries would like the opportunity to vote on whether they stay in, or leave the union.
45 of 6,000 people surveyed across Belgium, France, Germany, Hungary, Italy, Poland, Spain and Sweden said they wanted a referendum like the one that will be held in Britain in a matter of weeks.
According to the research from Ipsos-MORI, one-third of those voters want to leave the union.
The study did not include The Netherlands, the country recently saw a protest vote mobilise to defeat a routine EU trade deal with Ukraine as a demonstration of their opposition to Brussels.
Desire to leave 'Europe' is highest in Italy where the anti-EU 5-Star Movement has become the country's second-biggest political group.
It is second highest at 41% in France where the far-right National Front party wants to leave the single currency.
Appetite for an exit is lowest in Poland and Spain at 22% and 26%.
49% of the respondents think that Britan will leave the EU, and 51% believe doing so will hurt the European economy - while only 35% think it will hurt the UK.
David Cameron has invoked the risk of war in his latest warning about the dangers of leaving the European Union.
The Prime Minister said peace in Europe could not be guaranteed and it is in the UK's interest to be able to influence what happens to our neighbours.
Mr Cameron's key speech marked an upturn in campaigning, and will be followed by an address from Boris Johnson, who is expected to challenge the Prime Minister's claims.
Introduced by former Labour Foreign Secretary David Miliband, Mr Cameron said: "For good or ill, we have written Europe's history just as Europe has helped to write ours.
"The moments of which we are rightly most proud in our national story include pivotal moments in European history. Blenheim. Trafalgar. Waterloo.
"Our country's heroism in the Great War. And most of all, our lone stand in 1940.
"The European Union has helped reconcile countries which were at each others' throats for decades.
"Britain has a fundamental national interest in maintaining common purpose in Europe to avoid future conflict between European countries.
"And that requires British leadership, and for Britain to remain a member. The truth is this: what happens in our neighbourhood matters to Britain.
"That was true in 1914, in 1940 and in 1989. Or, you could add 1588, 1704 and 1815. It is just as true in 2016."
Additional reporting by IRN