On 23 June our nation faces a decision that will define its future. A once in a generation opportunity to either work to revitalise Europe, or walk away for good.
I will be voting to remain in Europe, and Unison will be encouraging its 1.3million members to do the same, following a comprehensive survey involving 60,000 of them. It's almost certainly the largest attitude survey conducted by any membership body on the EU referendum to date.
That position is something of a change of direction. Our union is not and has never been pro-EU. On the contrary, we've opposed decades of EU treaties - from Maastricht to Lisbon to the EU constitution - and have repeatedly warned against the slow drift towards dogmatic austerity across the continent. We'll continue to make these arguments.
However in the run up to the June referendum, we'll be urging our members to use their vote to keep Britain in the EU. Leaving would have a hugely detrimental impact upon rights at work, jobs, living standards and public services - an impact that everyone would notice.
That is not to say we believe the EU is perfect. Even the most ardent Europhile would struggle to defend the unelected but powerful commissioners, some of the continent's trade deals or its rigid and damaging adherence to free market economics.
But the world is an imperfect place, and it's always far better to work to change flawed institutions, than to walk away in search of a perfect option that doesn't exist. That's not how we negotiate with employers, and it's not how to get the best deal for the British people.
Negotiation within Europe has undoubtedly brought benefits to working people, many of which we'd lose by leaving. Because without Europe - and outside the EU - working people would lose out dearly. Whether it's maternity leave, paternity leave, guaranteed paid holiday, fair working hours, the right to proper breaks at work or equal rights for part-time workers, the EU plays a vital role in protecting the British workforce.
It's unlikely this crucial workplace protection we enjoy inside of Europe would survive a Tory government, or even a government of another stripe if the UKvotes to leave. We certainly can't entrust ministers who have introduced some of the most restrictive union legislation in the western world to stand up for British workers in the same way the much-maligned EU has.
The choice here is clear. Remain inside an imperfect Europe and work alongside social movements on the continent to reform it. Or turn our backs upon a union that, whilst flawed, has delivered unprecedented peace to our corner of theworld, leaving our rights open to attack from the neo-Thatcherites of the Tory right and UKIP.
So whilst the leave campaign makes several arguments to which many on the left may be sympathetic - and which remain campaigners must take seriously - they are not what they appear. They claim that if Britain left the EU, the money spent on Europe could instead be spent on the NHS. It's nice to see the right-wingers dragging our country towards the exit door are so concerned with our publicly-owned health service after years of undermining it and trying to sell it off, but it's a fallacy.
Of course, the government spends money on the EU. And of course our NHS (and all public services) need far greater resources after years of squeezes and cuts. But the fallout from the economic and political turmoil caused by an exit from the EU would - as it always does - fall disproportionately on public servants and public services, including the NHS. And of course those Tories who pine for Brexit also long for the privatisation and liberalisation of our public services in a Britain stripped of EU protection.
Anyone who tells you that leaving the EU would provide a boost to UK public services is neglecting to tell you they're also taking a risk with those same services, their funding and the lives of every public service worker. Our economy is already more fragile than most people imagine, and an EU exit could cause damage that would fall, once again, on the heads of the least well-off, rather than on the well-heeled members of the Eurosceptic elite.
After all, the debate about our nation's future is not - as it can often feel - a proxy battle for the leadership of the Tory Party. Many seem determined to ensure that whether we leave Europe or remain boils down to a battle between Boris and George or Michael and David. Yet this is an argument more important than party leaderships or even political parties. This is a debate that will define all of our futures, and those of generations to come.
It is a debate in which Unison and our 1.3million members must play a part. We will not be standing on the sidelines. We will be campaigning proudly for Britain to stay in the EU, and to rebuild it for the benefit of working people.
Dave Prentis is the Unison general secretary