The red Kipper flies at midnight!*

[Beskar]

I presume you mean being in the EU improves trade. Whatever you mean, IIRC the EU bloc is by some distance the biggest trade partner the UK has, and certainly the biggest we'll have without contributing massively to carbon emissions. On that basis, we'll need to have trade agreements of some kind with other EU countries, whether we're part of it or not. If we're part of the EU, we get a say. If we're not, we'll need to have those trade agreements anyway, but they'll push the rest of the package along without us having any say whatsoever (compare with what John Major did at Maastricht). If we don't like social regulations, we can, and have, leave out some of it without losing our say in the rest of the package. If we're in the EU.

Pretty much what I mentioned.

On another revolutionary step, I will say this. Having the European Union not be democratically accountable and invested as what some of the critics say, actually helps British nationalistic interest, because within the current system, being basically one of the 'big three' Britain has a vastly disappropriate influence within the European Trading bloc which is why France didn't want Britain to join in the beginning because of the dominance. It is why talks such as Merkel and Cameron at Downing Street are as high profile as they are.

So leaving the Union like some of the national sentiments want actually hinders and damages nationalistic self-interest compared to staying within the current status quo.

Admittedly, that does mean that me, who is wanting a more democratic and accountable EU is in a position of eroding Britain's nationalistic self-interest, but then, I am not a nationalist.