When David Cameron's Conservative party won last year's UK general election, one word was thrust into the spotlight, and hasn't really left - Brexit.
Months of frustrating, at times vicious, back-and-forth between the Leave and Remain camps will come to a head on 23 June, when the Brits head to the polls to decide their EU fate and perhaps that of the EU as a whole.
It is a debate that has split UK MEPs, with some fearing for their future and others actively campaigning to put themselves out of a job.
Glenis Willmott, head of the UK Labour delegation in the Parliament, has been busily travelling back and forth between Brussels and Britain, making the case to both the public and her UK party colleagues for continuing EU membership.
For her, a Remain victory is essential because, "the EU stands for internationalism and solidarity, helping those in need, countries working together to build a better Europe. Only by being a part of it can we improve the lives of working people not just in Britain but across Europe."
Willmott adds that; "Never before in human history have we had such an organisation, an alliance of nations, taking decisions for the common good, enriching the lives and opportunities of half a billion people. No other continent has anything that comes close."
Catherine Bearder, the UK's lone Liberal Democrat MEP, agrees; "The EU is a construct that has helped to deliver peace, human rights, cultural growth and prosperity to its citizens.
"We have peacefully welcomed countries that used to be our enemies into the EU and we work with them around a table, not by shaking our fists at them. Despite difficult economic times, environmental problems, movements of people, it remains the best place on earth to live."
This is, however, not an opinion shared by all. Roger Helmer, an MEP since 1999 - originally for the Tories and now for Ukip - dismisses the EU as; "A dysfunctional organisation that damages our economy and denies us freedom and self-government."
Meanwhile, his former-assistant-turned-Conservative MEP Emma McClarkin believes that the EU, "represents a bloated bureaucratic body focused on political integration, which lacks the ambition to compete globally," when in fact, "it should fundamentally be a trade area; that is what the UK voted to join."
Each side has passionate supporters, making it difficult to predict which one will emerge victorious in a few days' time. We asked our MEPs to look into their crystal balls; unsurprisingly, both camps are cautiously optimistic.
Willmott says that she is, "confident the majority of people, when presented with the facts about the campaign, will not want to take the risks that leaving entails."
Bearder agrees, although she warns that; "A referendum is always risky, with the possibility that it might swing one way or the other due to domestic politics or events closer to the day."
In the end, according to Willmott, it will all come down to voter turnout. "The opinion polls are fluctuating, some giving Remain a lead, some Leave, most within the margin of error. What is absolutely vital is that everyone votes, especially young people; they will be the ones that will have to live longest with the consequences of the referendum."
Helmer expects the outcome of the vote to be, "very evenly balanced. Difficult to predict, but the Brexit side has a good chance."
McClarkin also predicts a victory for the Brexiteers, saying; "I am confident that as UK citizens learn more and more about how much money we waste on Brussels and Strasbourg and see the bright future that we can have outside of the EU, they will vote Leave."
Once the result is known, what exactly will the future hold? The opposing sides have wildly differing expectations, with the Leave campaign insisting that Britain will thrive away from the influence of Brussels. Meanwhile the Remain camp warns that a divorce could trigger the breakup of the UK and even undermine the EU's future stability.
McClarkin wants to, "maintain a friendly trading relationship with the EU, but for the UK to be able to do trade deals with other countries around the world. EU trade negotiations have been painfully slow and we do not have any ratified free trade agreements with the USA, Canada, Australia, New Zealand or India.
"These are natural trading partners for the UK and I am confident we would secure trade deals with them easily and quickly post-Brexit, because we are an outward-looking country, ready to compete in a global marketplace."
Helmer agrees, viewing an ex-EU Britain as a "great trading nation; a good neighbour to Europe, not a bad tenant."
However, leaving the Union could take years; there are no precedents and no rules to play by, other than the elusive 'article 50', something many seem to know by name without actually knowing what it says.
Yet Helmer is defiant. "The UK will be the rump-EU's largest export customer and largest net export customer. We have a very large trade deficit with the continent, which gives us a very strong negotiating position.
"We shall have a free trade agreement within the Lisbon Treaty's two-year negotiating period. If the European Commission is dilatory in this regard, they will find the CEOs of major continental companies kicking their door down and demanding a trade deal."
McClarkin is also convinced the UK will continue to trade extensively with the EU. She points out that Britain will remain a full member of the single market for the duration of the renegotiation.
"It is in the interest of the EU – particularly countries such as Germany, as they sell far more to us than we do in return - to strike a free trade agreement with the UK. British businesses will still enjoy access to the single market because of such a free trade agreement, but we won't be tied up in overly bureaucratic EU red tape that is so damaging for our small businesses."
Bearder, however, argues that, "Around the world there is a huge and very sensible movement towards forming trading blocs. The UK leaving the EU would damage that process.
"The effect on the Commonwealth [countries] will also be great; I fear that this will encourage more countries to see that they have a better future linked to the EU than to a country outside that bloc. Currently their relationship with the UK gives them a direct link into the EU, however they would be less in favour of this arrangement if that influence no longer existed."
While McClarkin and Helmer refute claims that Brexit would lead to the breakup of the UK, there are fears that Sinn Féin in Northern Ireland and the Scottish National Party would use a vote for Britain to leave the EU as grounds for independence referenda. Willmott and Bearder feel this represents a genuine risk, with a vote to Leave likely to cause chaos in UK domestic politics.
"If Britain votes to leave," warns Willmott, "we can't be certain of anything, for the UK or for the EU. It would be hard to see how it would not embolden those on the Eurosceptic right like Ukip, which seek to capitalise on division and uncertainty. If anybody tries to tell you with certainty that they know what will happen in a vote to leave, they don't know what they're talking about."
Bearder warns that, "a vote to remain will be a huge blow to nationalists elsewhere in Europe. A vote to leave may encourage many far-right nationalists in Denmark, Sweden, the Netherlands and elsewhere to step up their calls for similar referenda. This could lead to the disintegration of the EU. We need to ask ourselves; who exactly would benefit from such a breakup?"
Unfortunately, given the EU's perceived inability to deal with a succession of recent challenges - chief among them the refugee and economic crises - it isn't always easy to sustain enthusiasm and faith in the European project. Still, insists Willmott; "The best way to deal with such cross-border issues is for countries to work together, to find common solutions to the crises we face."
"Those campaigning to leave the EU haven't got any answers on the economy. The benefits of being in the EU are obvious: we are part of a single market of 500 million people - the world's largest tariff-free trading bloc. Half our exports are to the EU; the average household would be £4300 (€5500) a year worse off if we left; millions of jobs depend on our membership; we are safer in the EU."
"Isolation rarely equals greater influence in the world and is certainly no guarantor of security or prosperity. The reality is that the EU will not go away if Britain is not part of it. An isolated Britain will still be hugely affected by developments on the continent, yet we will have absolutely no say on its rules and direction. This is a far weaker position."
What happens if Britain decides to stay? Will it not have lost its best bargaining chip? "Not so," says Willmott. "Working constructively within an organisation is far more likely to enable you to achieve your aims than threatening to leave will. It's time for Britain to be a leader in Europe again. For too long, British politicians were happy to take the credit for the positive work that Europe's done and blame the negatives on Brussels."