The Economist tweeted this graph this afternoon showing that the UK now sends the majority of its exports outside the EU. It offers an accompanying editorial comment that this chart will please eurosceptics. At first glance, you would think that it supports the ‘Leave’ campaign’s assertion that the UK can thrive as an exporting nation outside the EU, focusing on trade with the rest of the world. Actually, the graph shows quite the opposite.
Firstly, as @Shivoa points out, the UK benefits from many trade deals which the EU has negotiated with other countries in order to sell its products overseas. Outside the EU, the UK would no longer be party to those agreements and would have to renegotiate them on far from preferential terms, without the muscle which the EU has as the world’s largest trade bloc. Rather than accelerate the trend which this chart illustrates, Brexit would put it at risk.
Secondly, as this article on Conservative Home demonstrates, we are not talking about a zero sum game here. British exporters do not choose between the EU and the rest of the world. If exports to the EU fall, they do not automatically rise elsewhere. The Economist’s graph in fact illustrates (but also masks) a serious deterioration in the UK’s balance of trade over the same period. A fall in the UK’s exports to its primary, high value markets in the EU is a bad thing, even though it can be made to look like a shift towards non-EU markets if we ignore volume and look purely at percentages.
The ‘Singapore’ argument for Brexit is fallacious. Brexit would only harm British exporters, and that is why they overwhelmingly want the UK to remain in the EU.
Follow-up: I have to add this graph which was posted by @NauroCampos (Professor of Economics at Brunel University). It speaks, literally, volumes.