This week, the debate about Britain’s future relationship with Europe began in earnest. But it was started not by the people who will actually make the decision on our EU membership, but by big businesses seeking to save their profits.

JCB said its business would be fine without Europe, the CBI said businesses must make the case for the UK to stay in, but politicians and the public have been strangely quiet. Yet the Europe Union is not just a business opportunity. And whether we stay in or leave is not just something that affects corporate balance sheets.

The Green party wants to see a referendum take place. As it's been 40 years since the public last had a chance to vote on our EU membership, and there is clear public demand, we recognise that it is vital that a democratic decision is made by the British people.

But it is also vital that those who will be affected most by the outcome of that referendum are able to have a say. That’s why I’m backing our Young Greens in their fight to secure votes at 16 for the EU referendum. A precedent was set with the Scottish independence referendum that proved 16-18-year-olds are engaged and want a vote on decisions as vitally important as this. To deny our young people a say in their future would taint this referendum’s legitimacy.

For the sake of our young people, and of the British people, the Green Party will be campaigning hard from now on for Britain to remain a member of the EU. We recognise that reform is necessary, to make the EU more democratic, more accountable to its people, and to end the pursuit of dangerous trade deals like TTIP. But for the sake of our climate, our rights, and our cherished freedom of movement, we must stay.

Without the international targets that the EU can enforce, we don’t stand a chance of tackling climate change. As part of that union, Britain can become a world leader in pioneering renewable energy technologies and sustainability initiatives. With the EU, our voice is louder on the global stage when we push big polluters like the US and China to rein in their carbon emissions.

The EU is one of the biggest safeguards of our most fundamental rights. A Conservative government might repeal our British Human Rights Act. It might restrict legal aid to make it harder for us to appeal to the European Court of Human Rights. But as long as we remain a member of the European Union, our most basic rights – to life, to freedom of speech, to protection against slavery – will be protected.

The EU principle of free movement is set to come in for a kicking as this debate rolls on. But for the Green party the opportunity this right brings is something to be celebrated. That freedom to gain new experiences from working or studying in another country, or to learn from people with different backgrounds and experiences who move to Britain, is a great thing. We will stand up for migrants, and stand up for those opportunities.

The European Union brings a diverse group of countries together and helps them to achieve great things. It provides protection and opportunity for millions of people. And it gives us a genuine chance to tackle climate change across the world.

But it is also a champion of democracy. The British people deserve a chance to air their concerns about the future of Europe, and to decide whether they want to remain part of the EU.

As Green party leader I will work relentlessly to ensure that both sides of the argument on the EU are heard. I will argue that we ought to stay in, not just for the sake of British businesses, but for the sake of British people.

Natalie Bennett is leader of the Greens