EU leaders meet today and Friday for their last summit before the United Kingdom is anticipated to trigger Article 50 later this month, setting off formal exit negotiations. The two-day session will include focus on a new white paper launched last week by European Commission President Jean Claude Juncker on the future of Europe by 2025.

For while massive attention has focused on the impact of last June’s Brexit referendum for the United Kingdom, how the bloc itself changes will probably prove the more important, but the most overlooked, outcome of the vote. To this end, Juncker’s paper outlines five main scenarios for how the EU could evolve with a view to shaping debate and finalising a vision for the future that can potentially see the continent emerge from the current political and economic storm engulfing it.

The scenarios range from the EU retreating to no more than the current economic Single Market which seeks to guarantee freedom of movement of goods, capital, services and people. At the other end of the spectrum, however, is a quite different future where the remaining 27 member states decide to do much more together, reigniting European integration.

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Of the 5 scenarios, “Carrying on” is perhaps the most likely to be realised. This would see the EU muddling through from where it is today and seeking to deliver on the Bratislava Declaration agreed by all 27 non-UK member states last year. This manifesto includes better tackling migration and border security, beefing up external security and defence, and greater stress on enhancing economic and social development, especially for young people across the continent who have been badly impacted by the fall-out from 2008-09 international financial crisis, not least in countries like Spain and Greece.

However, even that middle range future is by no means certain in the current economic and political context. Further setbacks in coming years would instead see either a “Nothing but the Single Market” or “Doing less more efficiently” scenario come to pass. In either of these futures, the current scale of EU functions would be rolled back with attention and limited resources focused instead more on a smaller number of policy areas, including the Single Market.

Based on current trends, perhaps the least likely scenario to be realised by 2025 is “Doing much more together”. This would see all 27 remaining states sharing more power, resources, with decisions agreed faster and enforced much more quickly.

More possible, however, is the “Those who want to do more” scenario which would see more coalitions of the willing emerging in select policy areas to take forward the integration agenda on a flexible, rather than across-the-board basis. A model here could be the Eurozone where some 19 of the current 28 EU members have decided to enter into a monetary union with the euro as the single currency.

How Brexit affected Britain's favourite foods from Weetabix to Marmite Show all 8 1 /8 How Brexit affected Britain's favourite foods from Weetabix to Marmite How Brexit affected Britain's favourite foods from Weetabix to Marmite Weetabix Chief executive of Weetabix Giles Turrell has warned that the price of one of the nation’s favourite breakfast are likely to go up this year by low-single digits in percentage terms. Reuters How Brexit affected Britain's favourite foods from Weetabix to Marmite Nescafé The cost of a 100g jar of Nescafé Original at Sainsbury’s has gone up 40p from £2.75 to £3.15 – a 14 per cent rise—since the Brexit vote. PA How Brexit affected Britain's favourite foods from Weetabix to Marmite Freddo When contacted by The Independent this month, a Mondelez spokesperson declined to discuss specific brands but confirmed that there would be "selective" price increases across its range despite the American multi-national confectionery giant reporting profits of $548m (£450m) in its last three-month financial period. Mondelez, which bought Cadbury in 2010, said rising commodity costs combined with the slump in the value of the pound had made its products more expensive to make. Cadbury How Brexit affected Britain's favourite foods from Weetabix to Marmite Mr Kipling cakes Premier Foods, the maker of Mr Kipling and Bisto gravy, said that it was considering price rises on a case-by-case basis Reuters How Brexit affected Britain's favourite foods from Weetabix to Marmite Walkers Crisps Walkers, owned by US giant PepsiCo, said "the weakened value of the pound" is affecting the import cost of some of its materials. A Walkers spokesman told the Press Association that a 32g standard bag was set to increase from 50p to 55p, and the larger grab bag from 75p to 80p. Getty How Brexit affected Britain's favourite foods from Weetabix to Marmite Marmite Tesco removed Marmite and other Unilever household brand from its website last October, after the manufacturer tried to raise its prices by about 10 per cent owing to sterling’s slump. Tesco and Unilever resolved their argument, but the price of Marmite has increased in UK supermarkets with the grocer reporting a 250g jar of Marmite will now cost Morrisons’ customers £2.64 - an increase of 12.5 per cent. Rex How Brexit affected Britain's favourite foods from Weetabix to Marmite Toblerone Toblerone came under fire in November after it increased the space between the distinctive triangles of its bars. Mondelez International, the company which makes the product, said the change was made due to price rises in recent months. Pixabay How Brexit affected Britain's favourite foods from Weetabix to Marmite Maltesers Maltesers, billed as the “lighter way to enjoy chocolate”, have also shrunk in size. Mars, which owns the brand, has reduced its pouch weight by 15 per cent. Mars said rising costs mean it had to make the unenviable decision between increasing its prices or reducing the weight of its Malteser packs. iStockphoto

Despite the detail in the approximately 30 page white paper, the worst-case scenario of the bloc imploding is not included as a distinctive future for the EU. Nonetheless, given the build-up of challenges now facing the union – which go well beyond Brexit – this outcome cannot now be dismissed in the period before 2025.

Indeed, some 60 years after the Treaty of Rome, which was one of the EU’s founding treaties, European Council President Donald Tusk said last month that the threats facing the EU are now “more dangerous than ever”. He identified three key challenges “which have previously not occurred, at least not on such a scale” that the EU must tackle.

The first two dangers relate to the rise of anti-EU, nationalist sentiment across the continent, plus the “state of mind of pro-European elites” which Tusk fears are now too subservient to “populist arguments as well as doubting in the fundamental values if liberal democracy”. The EU chief is conscious here that, following Brexit, and US President Donald Trump’s election, it is continental Europe which will provide a lodestar in 2017 for whether right-wing populism will continue to find fertile electoral ground.

In elections in countries beginning with the Netherlands next week, where polls indicate the far-right Freedom Party could emerge as the largest single party, left-wing and centrist parties are under pressure from insurgency parties championing euroskeptical, anti-immigrant platforms. It is France, however, which alongside Germany has traditionally been the ‘twin-engine’ of EU integration, which will be the key election to watch in the continent.

The reason is the far right, National Front candidacy of Marine Le Pen who has called for closer ties with Russia, questioned the need for Nato in the 21st century, and called for a French referendum on the country’s EU membership. While she is not currently the favourite to win, she stands a realistic shot of getting to the second-round run-off election in May and Tusk and other EU leaders are well aware that if she pulls off an upset victory, it would be an even more savage blow to the bloc than Brexit, not least given France’s membership of the Eurozone.

The third threat cited by Tusk, this time external to the EU, is what he calls the new geopolitical reality that has witnessed an increasing assertive Russia and China, and instability in the Middle East and Africa which has driven the migration crisis impacting Europe. Intensifying this is the new uncertainty coming from Washington with Trump questioning much of the post-war tenets of US foreign policy, including broad-based support for European integration.

Taken overall, Juncker’s paper underlines that debate over Europe’s future will intensify as the formal Brexit talks between the EU and United Kingdom commence. Many leaders are scrambling to come to terms with intensifying internal and external challenges, and their decisions in coming months will define the longer-term economic and political character of the bloc in the face of what could yet become, collectively, an existential threat to the union’s future.