That the impact of mass and unrestricted immigration in working-class communities was a significant factor in the outcome of the EU referendum is undeniable. Yet, despite compelling evidence demonstrating this truth, many on the Left seem determined to remain with their heads buried firmly in the sand.
EU law providing for free movement of people was never the progressive instrument many believed it to be. It is one of the 'four freedoms' enshrined in the rules of the Single Market, along with the free movement of goods, services and capital. In other words, workers are categorised not as human beings, but explicitly as commodities, to be bought and sold like copper and coffee according to the laws of supply and demand.
Naturally, this commodification of workers is very popular with big business, enabling, as it does, bosses to take advantage of highly-diverse economies by shunting workers across borders and playing them off against each other, thus driving down wages. It is like outsourcing in reverse: no longer are firms forced to relocate abroad in an effort to save on labour costs; free movement laws allow them to do it while staying put.
This type of social dumping uproots workers and their families, atomises society, and militates against settled communities and the sense of place and belonging desired by all human beings. All in the name of greater profits.
Yet, to many in the Labour party and trade union movement, free movement (in reality, forced movement) is seen as an advance for working people, to be defended against all comers. For them, it's a building block to greater class solidarity and another step on the path to their vision of a borderless world. The actual impact on working people, migrant and native, is secondary.
Unprecedented levels of immigration into the UK have led to a substantial rise in cheap labour (causing downward pressure on wages), tested social cohesion like never before, and increased the strain on public services. The abject failure of Labour over many years to address these concerns - or even to recognise their legitimacy - has resulted in a fundamental rupture between the party and its traditional heartlands, so that millions of once-loyal Labour voters now abstain in general elections or have switched their allegiance to Ukip.
Likewise, the refusal of trade union leaders to take seriously the concerns over open-door immigration, and to instead resort to trite and superficial sloganeering, is an abdication of their responsibilities to those whose interests they were elected to serve, and has ensured that the movement is as disconnected from working people as it has ever been.
We trade unionists must of course stand with migrants and challenge any attempt to attach personal blame to them for the failings of government or the actions of unscrupulous employers. But there is no contradiction between showing solidarity with migrants on the one hand - such as by campaigning alongside them for decent wages and against discrimination - and opposing a policy of open-door immigration on the other. Immigration, properly managed, is a good thing. But just as rapid, large-scale and unfettered movements of capital have the capacity to cause social and economic disruption in local communities, so do those of labour. That is a reality that too many on the Left have still failed to grasp.
To be opposed to unlimited immigration out of concern for the impact on wages and social cohesion is not to be opposed to migrants, any more than to oppose unemployment for the same reasons is to be opposed to the unemployed.
Yes, we must challenge 'rip-off bosses' who pay low wages and a Tory government which does not invest sufficiently in public services. But it is utterly disingenuous to pretend that these problems are not made more acute by open-door immigration. Moreover, to concentrate solely on the economic aspects of the argument, as though unlimited immigration would cease to be a contentious issue if only wages and investment were higher, or if only voters could be persuaded to accept that overall it makes the country a little bit wealthier, is to miss the point. After all, it was the philosophy of Margaret Thatcher to reduce every policy issue to the dictates of the balance sheet, with no regard for the impact on society or community cohesion. No socialist or trade unionist should do the same.
And those who argue that concerns over unlimited immigration exist only as a consequence of profound economic hardships should be reminded that the likes of Ukip and the BNP grew in strength across the country long before the global financial crisis struck.
Poll after poll has demonstrated that unlimited immigration is a major concern for the working-class. Most of these people are perfectly decent and tolerant, as indicated by a post-referendum ICM poll which showed that 77% of Brexit voters believed that EU nationals already living in the UK should be allowed to remain. Far from being racist or xenophobic, working-class voters are imbued with an instinctive sense of fairness. But their good faith has been abused. That's why the tactic employed by some on the Left of deflecting genuine concerns over unlimited immigration by accusing opponents of 'blaming migrants' and 'pandering to the bigots' is insulting and wrong.
Few things have corroded the relationship between working-class people on the one hand and their leaders in the Labour party and trade union movement on the other than the obstinate refusal of those leaders to treat concerns over unlimited immigration with the legitimacy they deserve, and to instead resort to boilerplate and patronising slogans.
We on the Left cannot remain in denial on this issue. An attitude of 'No compromise with the working-class over free movement' will no longer wash. That's why the Labour party and trade unions must support an end to free movement. A failure to do so would further damage - and possibly shatter for good - the already-fractured relationship between them and the people they claim to represent.