UNISON’S announcement that we are to campaign to Remain in the EU referendum may have come as a surprise to some on the left.

As a union we have a proud track record of opposing EU treaties from Maastricht to Lisbon, and warned repeatedly of the relentless drift to free-market dogma and permanent austerity politics.

We have also been at the forefront of the campaign against TTIP, the trade deal that could decimate public services and give power to multinational corporations to sue nation states for daring to protect workers or for imposing regulations which make product safety more important than profit.

So, does the decision to support a vote Remain campaign mean we have abandoned these principles and Unison is now a pro-EU cheerleader? Of course it doesn’t. Our opposition to TTIP will remain and we will continue to criticise any EU action that we believe damages our members or the services in which they work.

But those same members took part in one of the most ambitious consultations we have carried out as a union.

Overwhelmingly they told us that the EU referendum was a crucial issue, that Unison should be part of the debate and take a position, and that our position should be to Remain.

Across the south-west, 20 branches submitted responses in the consultation, placing workplace rights and public services at the top of the list of concerns.

Branch debates considered the impact of losing the protection of TUPE when services are outsourced, or wondering which private-sector care home or contractor would be first in the queue to abolish paid holiday when it was no longer a legal requirement.

There can be no doubt that our movement has leaned heavily at times on European law as a protection against the onslaught of Thatcherite policies and the drive to privatise every public service. Those who say this signifies a weakened trade union movement may even be right. And if they are, this is no time to be casting aside any protection on which workers rely.

The vote on June 23 will not have an “end austerity” option. Nor is it a vote to abolish the EU. It is a vote on whether British workers are better off as part of the EU or whether we would be better off leaving the EU.

Sitting on the fence may seem an attractive option to some. But we have decided to take a stand and take a side.

We will continue every effort to reform the EU and make it a Europe for workers and not the bosses.

We still believe that right now the best decision is to vote to Remain. We also believe that a vote Leave victory would embolden the hard right of the Tories and re-energise Ukip, meaning we could see an even grimmer future for workers in Britain. This cannot be allowed to happen.

The South West TUC AGM will be debating the EU referendum this weekend, hearing from our sole Labour MEP, Clare Moody, and Elena Crasta from the TUC Brussels office. In the room will be unions that support the Remain campaign, some that have no view and some that will be campaigning to Leave.

Trades councils in the region will also have a range of views and the discussion will be lively, informed and passionate. But most importantly, all of us need to remain united against the real common enemy — this current government and every single faction within it.

On June 24 the Tories will still be in power and the machinations between David Cameron and Boris Johnson may provide sideshow entertainment for the political elite, but trade unions will still have many battles to fight and win.

This week saw us win one of those battles in defeating the government plans to remove check-off (automatic deduction of union subscriptions from workers’ payslips) in public services. Let’s not allow this referendum to divide us.