We will vote to stay in

I welcome the Prime Minister’s initiative to have a referendum. I believe that the United Kingdom faces a big constitutional moment. I am not sure that that was faced in 1973 or in 1975, because the EU, undoubtedly, has an economic and political dimension now. I believe that it was always implicit that the EU would have a political personality at some point — it was what the founding fathers desired.

Therefore, it is hardly surprising, given the experience of the European states in the Second World War, when the classical state concept — which was fully developed in the 19^th Century — was destroyed in Europe. Most states could not even defend their own borders. They have looked at the whole political space and asked some fundamental questions.

Our experience was very different in that our state did survive and indeed had one of its most glorious moments. However, we live in this moment and what we decide will affect generations to come. This is not just a debate for us here today or in five years; we have to really reflect on what we are going to do.

I want to say a couple of words about the implications for unionists and nationalists, which is key as we consider Europe and as we approach another big constitutional moment in the Scottish referendum. I say to Eurosceptical unionists that you face a very severe question if you are not careful. On all these issues, you will be arguing on the one hand that the Welsh and Scottish nations can prosper in a British union, when you are also saying that Britain cannot prosper in a European union. That is a fundamental contradiction in unionist thought.

Unionism has always been an expansive ideology, which believes that countries can join together to create wider constitutional and political entities. That is what unions are all about. We do not have to say that nations and states must necessarily be coterminous. There are other options for us. Nor will Britain ever survive, in my view, by being the last place in the British Empire. We will only survive by helping to shape the British political space.

However, I also think that nationalists have to ponder quite a difficult question. You could end up saying that Wales, and indeed Scotland, can prosper in a European union, but somehow, that this nation building cannot go on in a British union. That is also a fundamental contradiction. Nationalism would risk losing some of its hard-won liberal credentials if that sort of argument gets advanced.

I believe, in all of this, that we have a constitutional, fiduciary duty to take these constitutional moments very seriously. Constitutions are not fashion accessories. What we do in the next few years could affect the destiny of Britain, whether indeed Britain survives, and also the manner and character of the European political entity that is now emerging. This will be determined for 40, 50, 60 years and beyond, so we need to reflect very seriously on these questions. However, there is one basic principle that I will come back to all the time: trust the people. I would be very surprised if 60 per cent do not vote in favour of the EU whenever that poll is held.