The Green party is massively in favour of staying in the EU, despite seeing its many flaws as an organisation. The majority view of Greens is that its benefits far outweigh the problems. Personally, I disagree and when I stood for internal selection for the European parliament some years ago, I did so while making my doubts very clear.

Why do I disagree with so many of my colleagues, on this matter? Well, let me start by noting that I agree with the Green party’s assessment that the EU is in need of wholesale reform; I just don’t believe that it is reformable. Even if it is reformable, many of the reforms that others have made or are pushing for make it worse, as has been argued. So while I agree with the Green party’s quite negative analysis of the EU as it is, I just can’t support the idea that we must stay in to reform it.

Brexit is necessary to protect NHS from TTIP, says David Owen Read more

In particular, David Cameron’s forcing through of a stronger deregulatory agenda worries me. If the EU is worth having at all (I don’t think it is, but IF it is) then it is worth having mainly because of some of its labour regulations and environmental regulations. But those are exactly what rightwingers such as Cameron and George Osborne have in their sights: they are a central aspect of what Cameron and Donald Tusk agreed could potentially be got rid of in the recent deal. It is therefore completely wrong-headed to represent Cameron’s deal as a good basis for staying in the EU. In fact, from the Green point of view, it strengthens the case for leaving.

I confess that I have been disturbed over the past few months by a lack of willingness on the part of most of my Green colleagues to acknowledge the (on balance) overwhelming downsides of the EU. Instead, a somewhat Pollyanna-ish attitude seems to have taken hold, of the EU being praised much more than it deserves.

The most profound weakness of the EU, from the Green point of view, is that it is a super-sized top-down dogmatic project of endless industrial development and growth. It fosters the pointless carting of goods enormous distances, and it smashes local resilience and self-reliance. Often well-intentioned environmental policies are outweighed at every turn by the more fundamental drivers of its bid to turn the whole of Europe into a paradise for (environmentally damaging) agribusiness and industry.

This flagship of the EU’s common agricultural policy is still damaging our remaining farmland. It is still ripping up sustainable traditional methods of farming in eastern Europe and replacing them with unsustainable heavily industrialised agribusiness. The bottom line is this: EU agricultural policy undermines its own environmental policy.

Moreover, the EU is in effect (and, sadly, not unwillingly), at the mercy of big corporates and private interest groups, as I’ve previously argued. For example, look at the influence over many years of the car industry in pushing diesel, which has helped to poison the air in many of our towns and cities. Of course, the EU is now helping to clean our polluted air by threatening financial penalties, but this problem of killer air pollution was caused by the EU.

The power of corporate lobbying is a constituent feature of the EU. There is no European public. There are still separate national publics, and there surely will be for as far ahead as we can see. This creates a paradise for lobbyists, who can (and do) act unhindered by media or public scrutiny to influence the places where real power lies in Brussels, that is with the commission and within the even-more-secretive council. The logic of the EU, if it is ever to be democratised, is to become a United States of Europe. The euro is a Trojan horse to achieve this goal of fiscal and political union. Either one needs to be a federalist, or one needs to ditch the EU. Cameron, Jeremy Corbyn and the rest are trying to have it both ways. It’s an unstable halfway house, and will fail, as in effect the euro has already failed.

In any case the EU exists on too large a scale for genuine democratic oversight and accountability. The Green party believes that small is beautiful – and the EU is gigantist in its very nature. Economic growthism and constantly increasing the scale of economic activity and of trade and capital flows are both outdated ideologies. The future (if it isn’t to be very grim indeed) will be more resilient, smaller scale, and will focus on wellbeing, not on “growth” in the meaningless and damaging stat that is GDP. The EU is simply the wrong kind of entity for this future.

I understand the view that leaving the EU also leaves us at the mercy of rightwing elected bigots, but that’s an argument for changing our government, and for changing our voting system to a fairer one, not for staying in the ​EU.

People sometimes say to me: how can you campaign on the same side as Nigel Farage and George Galloway? Of course, it’s easy to return the compliment; how do those people contemplating a remain vote feel about being on the same side as Peter Mandelson, Osborne and Goldman Sachs? But the truth is that this issue is much bigger than party politics and personalities. Every party is divided on this issue, and rightly so. For it transcends ordinary party politics.

But, that said, I believe strongly that the Green case for exiting the EU is, on balance, much more authentic than the Green case for staying in. The EU is constitutionally wedded to the outdated and harmful project of heedless economic growth and industrial over-development – at a time when we need to stop living as if we have three planets to spare and not hurtling ever faster over the precipice. The EU is a congenital undemocracy built for big business and secretive lobbying to thrive in and built to resist the scrutiny of a genuine public. The EU is an outsized behemoth that simply doesn’t fit with the Green vision of a future lived on a more human scale.

My message to Green voters and anyone undecided on this issue is don’t give in to Project Fear. Let’s be bold enough to believe that we can mobilise the British people to fight for a greener, better Britain. To stand up for bees and for workers’ rights. To stand up for the NHS and against destructive “free trade” agreements.

Outside the EU, in a political system that, for all its flaws, has at least some meaningful scale and centres of power, we can do that. Inside the EU, our NHS will be whittled away by TTIP, our chances of taking the railways back into public ownership will diminish, and there will be nothing we can do about it.

Well, let’s do something about it … vote leave.