The world, especially the political world, is a volatile place these days, and one ought to be wary of omens. But when McDonalds announced this week that it would award its employees their biggest pay rise in a decade, you could be forgiven for having a superstitious moment about 2018. McDonalds, of course, won’t admit that the move was a concession to strike action by its workers, but the message could not be clearer. It is possible for even the most exploited workers to beat even the biggest of companies, so long as the action is high profile and militant enough.

The partial success of the McDonalds strikes should be cause for reflection in the wider left. They come as part of a new wave of industrial disputes, in which hyper-exploited workers outside of the labour movement’s traditional base base have waged vital campaigns inside the “new” economy and besieged public services – from Deliveroo drivers, to the Picturehouse workers, to the Durham teaching assistants and even the junior doctors. But overall, the British trade union movement is still historically weak. At a time when public opposition to austerity has risen, union membership has fallen.

2018 should be the year that the left prepares for government. Crucial to its ability to implement a radical programme will be having a grassroots movement that is willing to go on the offensive against big business, just as big business attacks the new government. As generations of Conservative administrations have recognised, the power of workers in workplaces is really about power in society. The legacy of a government led by Jeremy Corbyn will not just be measured in reforms passed from on high – it will be measured in the existence of a dynamic, democratic labour movement which gives ordinary people political agency and real, tangible power in their daily lives.

There are broader strategic issues in how Britain’s trade union leadership has handled the campaign against austerity and the emergence of the gig economy – and it is no coincidence that some new high profile campaigns have been run by smaller or newer unions. But to a great extent the problem is simpler: the law. Workers in Britain cannot strike in solidarity with their colleagues, cannot picket unless “supervised”, and can only strike on grounds of self-interest after a several week-long notice period and a balloting process running on paper to home addresses. This isn’t normal – these are the harshest anti-union laws in Europe.

Some of the worst aspects of this regime come from the 2015 Trade Union Act – but many date to laws passed under Margaret Thatcher and John Major which were left untouched by Tony Blair and Gordon Brown. In government, Jeremy Corbyn could scrap the anti-union laws, rebalancing the relationship between employers and workers and kickstarting a new generation of left-wing civil society. What’s more, he’d have the direct support of his party. A motion passed in September 2017 at the Labour Party conference pledged Labour to “repeal the Trade Union Act and anti-union laws introduced in the 1980s and 90s”.

Although both Corbyn and John McDonnell have expressed their opposition to anti-union legislation, the Labour leadership has been reticent to launch a full campaign or put it in a manifesto. Yet if they went for it, an overwhelming majority of the party ought to back them. The motion at 2017 party conference was moved by USDAW and the GMB, both of whom backed Owen Smith in the 2016 leadership election. In the wake of the Gate Gourmet dispute in 2005, when baggage handlers illegally walked out in solidarity with sacked catering staff at Heathrow Airport, stalwart moderate Roy Hattersley wrote: “Solidarity is no longer fashionable - indeed, in industry and commerce it is illegal. But in a decent society it ought to be encouraged rather than condemned […] Secondary action is more than necessary. It is right.”

The big task at hand, then – and one which is already being accomplished by workers at McDonalds, Picturehouse, Deliveroo and in the public sector – is to reframe the role of trade unions in society. For a generation of right wing and centrist commentators who imbibed the orthodox narrative about the 1970s and Thatcher’s “modernisation” of the economy, unions are threat to stability and democracy. For anyone experiencing the fresh hell of the collapsing neoliberal dream, trade unions ought to be understood as the guardians of public services and a tool for fighting exploitation and precarity.

Whatever happens, we should be clear that enacting socialist policies cannot be done merely from above, and that nurturing a mass movement is not optional. Its most fundamental building block remains the power of organised workers, and in order to liberate that force, Labour must commit to scrapping Thatcher’s union laws. Doing so will require the Labour leadership to take on the right-wing press and present an alternative narrative about trade union power. Given their record in 2017, there is every reason to be optimistic about their prospects.