British PM at European Summit, March 2015. Demotix/ Jonathan Raa. All rights reserved.

As the unions debated Europe at the TUC in Brighton this week, they and Jeremy Corbyn seemed to agree on one key thing: that David Cameron must not have a carte blanche to negotiate away workers' rights as part of his desired EU reform package ahead of the in-out referendum.  

The TUC, in a dramatic move, voted to shift its long-standing support for the EU to a ‘no’ if workers’ rights were diminished or removed in Cameron’s reform package. Labour’s position meanwhile is confused.

Shadow foreign secretary, Hilary Benn, continues to insist Labour will never call for a 'no' vote on the EU, but the new Labour leader has yet to clarify his position, although shadow chancellor, John McDonnell, says too that this will depend on what reforms David Cameron negotiates.

Leading unions including Unite and the GMB are supporting the TUC, calling for their members to vote 'no', if Cameron gets any deal from Brussels which permits the watering down of workers' rights.

But this is a risky strategy – workers' rights will not be stronger if the UK ends up outside the EU; it risks being a 'cut-off-your-nose to spite your face' strategy.

With the most recent opinion polls showing the gap between 'yes' and 'no' sides narrowing, the position of both Labour and the unions is increasingly important in the battle for public opinion. As the Tories bizarrely call upon pro-EU business to 'shut up' until later, pro-EU voices on the left need to be heard clearly now, not threatening a 'no' campaign.

One irony here is that it was the TUC much more than the Labour Party or Labour governments that defended workers' rights in the EU over the last two decades. New Labour did indeed end the Tories' opt-out on EU social policy (the 'social chapter' as it was called) back in 1998. They did so with the very clear aim to then limit and obstruct almost all new EU laws in this area. It was left to the TUC to be a clear British voice arguing, from a pro-EU stance, in favour of new directives (that did eventually pass despite UK/Blair government opposition) from the information and consultation directive (giving some weak rights to workers in large firms to be consulted in the face of major restructuring) to the temporary agency work directive (giving important rights to temporary workers).

But are the unions right: is Cameron aiming to undermine such positive EU employment laws in the UK, as the Tories successfully did back in the 1990s with their across-the-board opt-out?

The Financial Times reported in August that Cameron had scrapped demands for a new broad opt-out from EU employment laws, but that he was still looking for ways to ensure that the UK's opt-out from the working time directive (where the individual worker can choose to work more than 48 hours) would continue. Relatedly, the Tories also wanted to weaken European Court judgements that have impacted on rights concerning holiday pay, on-call time, and  rest periods (all also covered in the working time directive) – all measures the TUC emphasised in its vote.

If the FT is right, the Tories are apparently not attempting to return to a full-scale social and employment policy opt-out. Nor would they be likely to get one: the 1990s UK opt-out was deeply unpopular in the other member states, and while the member states are reluctant to move much or at all, even on some of Cameron’s priority areas, notably on the EU’s free movement of labour - any UK-specific changes to employment directives will not be well received, and will be seen as an attempt to unbalance the EU’s single market level-playing field and even to challenge the remit of the European Court of Justice. 

But the unions are surely right to campaign against Cameron attempting to weaken any of the existing EU rights. Labour should do so too, seeking the support of other member states in calling for no more UK opt-outs on workers’ rights. Since these issues are not at the centre of Cameron's list of demands for EU reform in the way that the issues of migration and EU freedom of movement are, pressurising him to drop them, and calling on other member states not to agree to these reforms, can be a successful strategy.

The real challenge for the unions is that their threats of campaigning for a 'no' vote in the face of any weakening of workers' rights is a 'nuclear' option that does not add up – unless they are anyway opposed to continuing EU membership (in which case surely they should just say so). By staying in the EU, workers will continue to be protected by most existing EU social and employment laws, even if Cameron was to secure any of his demands linked to working time.

And a Labour government – or any other progressive government in the UK – can opt back into any areas that the Tories did succeed in opting-out of, as long as the UK is still an EU member state.

A much bigger attack on workers' rights would result if the UK left the EU. Then it would be straightforward for the Tory government to repeal other directives protecting workers' rights –  obligations to implement EU laws would cease, and so leaving the EU would worsen not help workers' rights. And joining the EU again in the future would be hard – it would need a new referendum, and new negotiations with Brussels.

So the unions are surely right to tell Cameron he will make it more difficult for them to make a strong case for the EU, if he weakens workers' rights. But they are quite wrong to threaten to make the case for exit.

Staying in the EU with most or all existing social and employment laws still applying has to be a better outcome for workers than leaving the EU and finding that none of those laws apply any more. The unions are perfectly capable of campaigning for workers' rights against the Tories, without invoking the nuclear option of 'Brexit', yet this is the option that the TUC has now chosen.

Despite Cameron's emphasis – much of it bluster – on his negotiation with EU partners over reforms, at the end of the day the referendum is not a vote on what Cameron squeezes out of a reluctant Brussels. It is a vote on remaining in, or leaving, the EU. Those who prefer our membership of the EU as it is today, rather than with additional Cameron reforms, or who would like different progressive reforms to the EU, need to stay in to argue for this. Voting to leave, is not a vote against Cameron's reforms (whatever he manages to achieve); it is a vote against the EU, a vote for the UK to be entirely on the side-lines. Labour and the TUC should be arguing for the sort of EU they want, not walking away.

Any union that does argue for the UK to leave the EU – whether as a general argument or as a response to Cameron's reforms (once our EU partners agree any) – needs to explain how the UK being outside the EU will in their view strengthen workers' rights. And they need to explain how the UK, from the outside, will relate to the EU, and link up with other progressive parties and unions, who will all still be working together inside the EU.

It is certainly a tough time to argue a positive case for the EU – from the continuing failure to tackle the refugee crisis to the tough and damaging measures imposed on Greece. But splendid isolation is not a good alternative. Cameron chose a referendum to deal with Tory divisions on Europe; for the unions to align themselves with Tory eurosceptics arguing for 'Brexit' is a sad day for the UK, the EU and the labour movement.

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