As David Cameron goes into battle in Brussels over the European Union budget, we ask: What would the UK be like outside the EU? Would it be better or worse off? #exiteurope

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Jon Snow's unscientific poll of Eurostar travellers at St Pancras on Thursday evening (see film above) revealed a range of opinions, both in favour of and against Britain remaining inside the European Union.

But the latest opinion poll, published in the Observer on 18 November, showed that 56 per cent of Britons want to leave the EU. The issue for the people of the UK is no longer about the common agricultural policy or the working time directive - it is about the country's entire relationship with the EU.

With Prime Minister David Cameron in Brussels for two days of hard negotiation about the EU's budget, Britain faces the eventual prospect of a referendum that could lead to an exit from Europe.

Arriving in Brussels on Thursday morning, Mr Cameron indicated that he was not happy at the prospect of any increase in EU spending. And he is not the only leader to land in the Belgian capital armed with a list of demands.

But many of the others have already made it clear they see the British premier as the principal obstacle to any compromise deal.

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In or out?

Channel 4 News has been looking at what would happen if the United Kingdom decided to leave the European Union. In terms of the EU budget, Business Correspondent Sarah Smith found that, based on 2011 figures, the £5.8bn yearly EU contribution could fund 1p off income tax and a 4.5p reduction in fuel duty.

As far as UK trade is concerned (see film above), nearly half of the UK's total trade is with EU countries - and UK-EU trade has grown by 54 per cent in the last decade. However, our trade with the rest of the world over the same period has increased by 105 per cent - so it is not clear if the UK would do better inside or outside the union.

Migration is among the most controversial aspects of Britain's relationship with the EU. Leaving the union would mean we could control our population flows - and, of course, it is immigrants from countries like Poland that people notice the most.

But the fact is that the UK chose to allow free access from EU countries. What is more, there is significantly more immigration from the rest of the world: in 2011 314,000 people moved to Britain (see film below).

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The #exiteurope debate

Channel 4 News asked viewers to tweet their responses to the EU debates on the programme on Thursday's programme. The responses, predictably, were as polarised as the views expressed by Jon Snow's Eurostar interviewees. Here is a selection of those in favour of remaining within the union.

Tweets opposing continued membership of the EU were equally forthright.