The next three months will be crucial for the future of work in general, and for British trade unionism in particular. There are two threats. The first is the trade union bill – surely one of the most pernicious pieces of proposed legislation in recent history. The second, the possibility of leaving the European Union – so suspending the array of protections it offers in the workplace – would erode what remains of British worker rights and entitlements.

Britain already possesses the least regulated labour market in the developed world. The evaporation of these last protections will reduce employees to pawns – notations on spreadsheets to be disposed of at will in just-in-time workplaces. The division in Britain between an aristocracy of privileged workers enjoying international standards and a mass precariat of the rest will grow more acute. Brexiteers cheer at the prospect; the “burden” of Brussels regulations that they rail against fall into two main clusters. Firstly there are those essential to creating common standards and protocols in a single market of 28 countries and 500 million people. To complain about these is as futile as complaining about the weather. In or out they are vital to sustaining a level playing field as a precondition for trade. The only question is whether we want to share in their formulation.

The other cluster of regulations relates to minimum worker rights. No leading Brexiteers have ever committed themselves to maintaining them if Britain leaves. Nor will they. The economic case for leaving comes from the same intellectual stable as the trade union bill. In this universe, workers are not conceived as part of the capital of the workplace, assets whose energies and commitment need to be harnessed and whose humanity respected. Rather they are seen as problematic liabilities – costs to be minimised – that get in the way of “wealth generation”, a top-down process, initiated only by senior management and entrepreneurs which any worker entitlement necessarily obstructs.

Plainly there is a balance to be struck. Too many worker entitlements can stifle the agility of an enterprise and overload it with cost; too few and the world of work is turned into a high risk, unfair hell. This is bad for companies who are forced into a race to the bottom that is hardly the route to innovative capitalism; and bad for wider British society. A mass precariat will find it difficult to become great parents, active citizens or even provide a discerning mass market on which production depends. The balance struck during the years of the Labour and coalition governments is about right: Britain has a labour market that has proved remarkably good at creating jobs while most work environments are tolerable, offering minimum protections – even if the prevailing dynamic is to continue to load more risk on employee shoulders. Trade unions get a terrible press, even with only 2.7 million members out of a private sector of 19 million, and 3.8 million among the 7 million public workforce. But despite their demonisation, their efforts – on wages, discrimination, safety and fairness – along with EU provisions together create the balanced workplace. It is that which is now fatally threatened.

The recent qualifications imposed on the trade union bill in the House of Lords mitigate some of the worst of what was intended – but still it remains destructive. It is stunning that unions were legally to be prevented from electronically balloting members in a digital age for fear it might make compliance with tough balloting requirements easier – the House of Lords has instead demanded a review of the issue. Similarly it has tried to soften measures on political party funding.

But the bulk of the bill remains intact. Strikes, already difficult to call and win – and in any case at an all time low – are to be made even harder to call and easier to break. Ominously police powers to regulate protests and pickets are to be vastly extended, for example with a requirement to create “picket supervisors” who must wear identifiable armbands – just as police states around the world require. To cap it all, a newly empowered certification office will be able to investigate any union at any time even if no complaint has been made, calling any witness it likes – again a familiar tool of police states. Britain’s press, loud in defence of any regulatory intrusion on its rights, on this ominous evolution of a British authoritarian state is mute.

Anybody who imagines that in this culture, a post-Brexit Conservative government would legislate to retain the rights for information and consultation required by European law, women’s rights when pregnant, limitations to the working week and the rights for temporary, part-time and agency work is sadly deluded. Belatedly the unions are recognising the danger. The executive of Unite, our biggest union, has voted nearly unanimously to campaign to stay. So has the GMB, and Unison, more Eurosceptic, looks likely to follow. Frances O’Grady, general secretary of the TUC, makes a powerful case for staying. But it is a campaign struggling to find its voice.

For a start, the attitude of Labour leadership makes any common cause – either with unions or the wider Remain coalition – difficult to create. Too many on the left, in particular Corbyn, his close coterie and their supporters in Momentum, only want to campaign – if they campaign at all – for another “social” Europe that does not exist. They hold their noses at the Europe that is, with its necessarily complex tradeoffs and inability to represent a socialist Jerusalem. Certainly they never want to sully themselves with sharing a platform with members of the wider coalition, from David Cameron through to the CBI. But there is only the Europe we have: it has enough critics in the Leave campaign without half-hearted, qualified semi-advocacy from Corbyn. The CBI likes the single market; the City likes being the EU’s financial centre; the military and security institutions like the co-operative access; and British workers like the rights and entitlements. In the same way different interest groups might campaign for, say, a thriving parliament – notwithstanding political divisions – so should different interest groups come together for EU membership.

Cameron could help the unions by calling off his dogs of war on the union bill, accepting the Lords’ changes and dropping the most contentious clauses. He needs the unions to make common cause. In any case, a liberal Tory should not be trying to create elements of a police state. But equally, the centre-left must recognise where its interests lie. Brexit would move the centre of gravity of British politics enormously to the right – and that would be felt by most people soonest in the workplace. Time to campaign, to mobilise and speak for Europe as it is instead of a make-believe nirvana. There are only three months left.