Whatever the result of today’s referendum on continued UK membership of the European Union, it marks a watershed in political life in Britain and throughout the continent.

The referendum was called by Conservative Prime Minister David Cameron to placate the Eurosceptic wing of his own party and stop the UK Independence Party (UKIP) from gaining further ground at Tory expense. His disastrous political miscalculation threatens instead to split the Conservatives in two, hasten the demise of the EU and precipitate a major economic crisis globally.

Economically, the real issues being fought out are over whether the British bourgeoisie is best served by remaining part of the Single European Market or, in the words of the Leave advocates, repositioning itself “out of Europe and into the world” in order to better exploit opportunities in China, India and the Commonwealth countries.

Both sides—Remain, led by Cameron and Labour Party leader Jeremy Corbyn, and Leave, led by Tory Boris Johnson and UKIP leader Nigel Farage—shroud their real concerns in lies about defending jobs and vital social services and ensuring prosperity.

In reality, the EU defended by Remain is an instrument for imposing savage austerity, as has been so cruelly demonstrated in Greece. But Leave wants only to free big business and the City of London from what little remains of labour legislation and match the benchmark set by the conditions facing workers in the Far East. Whichever faction wins, the offensive against the working class will resume with a vengeance on June 24.

Never before has there been such a concerted intervention of leading figures from the Armed Forces and the security services MI5 and MI6 into political life. Both sides proclaim their commitment to NATO and its ongoing offensive against Russia and China. The Remain camp argues that British membership of the EU and the EU in general strengthen NATO, while the Leave camp maintains that British membership ties the UK to plans, pushed above all by Germany, to create a European Army, which will undermine NATO and raise the spectre of Germany establishing its unchallenged hegemony over the continent.

To conceal these political realities of class war, trade war and military war, and to sow divisions within the working class, the referendum has increasingly focused on whipping up nationalism and xenophobia.

The many social problems resulting from the savage austerity measures imposed by the ruling elite and its parties are blamed again and again on migrants. Again, Remain and Leave differ only as to whether anti-migrant measures require the EU’s “Fortress Europe”—guarded by razor wire fences, gun boats and concentration camps—or whether the UK must “take back control” of its borders and end the free movement of European labour into Britain.

The toxic stew this has created—such that UKIP’s campaign material is redolent of Nazi propaganda—pollutes social and political life and strengthens the forces of the far right.

Last Thursday’s murder of Labour MP Jo Cox by a fascist is a grave warning to workers and youth of the implications of this descent into nationalist reaction. It marks a new stage in the class struggle in the UK that will take on ever more brutal forms.

Cox’s killing was not the action of a disturbed loner, but a political assassination. It was prepared over decades by the incessant scapegoating of immigrants, the whipping up of nationalism and the paralysing of the working class by the Labour and trade union bureaucracy, which has allowed social reaction to deepen without an effective challenge from below. However, all those who claim that the filthy propaganda of the referendum campaign played no part in triggering this outburst of deadly violence are lying to cover up their own political responsibility.

A particularly criminal role has been played by the pseudo-left groups—whether they are aligned with the pro-EU agenda of Remain or have allowed the Tory right and UKIP to posture as “friends” of the worker by backing the anti-EU camp.

This applies above all to the organizers of the Left Leave campaign, such as the Socialist Workers Party and Socialist Party. Their insistence that political principle must be subordinated to the hope of the referendum splitting the Tories and hastening the coming to power of a Labour government is used to legitimise a political alliance with the most reactionary sections of the bourgeoisie.

There is nothing accidental in this. When George Galloway, the former Labour MP, declared on a platform with Farage, “Left, right, left right, forward march to victory on the 23rd of June,” he gave voice to a political tendency that is emerging not just in the UK, but internationally—a realignment of ostensibly left figures with right and far-right tendencies on the basis of nationalism.

In Ukraine, this took the form of an alliance with Svoboda and similar fascistic groups in the so-called “Euromaidan” coup engineered by Washington in 2014. In Greece, it was an electoral alliance between Syriza and the Independent Greeks. In the UK, sections of the pseudo-left, together with some Stalinist-led trade unions, insist that Boris Johnson and Farage, with their “millions of voters,” must be entrusted with the task of bringing down Cameron. Their stated or unstated goal is for national protectionist measures to be applied by a Labour government, including ending the free movement of European labour.

An unbridgeable gulf separates the Socialist Equality Party from these rightward careening forces. They articulate the efforts of a wealthy layer of the middle class to protect their privileged existence through class collaboration and a return to the nation as a supposed shield against the forces of globalisation.

The SEP bases itself on a struggle for the unity of the European and international working class against globally organised capitalism. It refuses to lend the slightest support to either faction of the ruling class in the referendum campaign. We call for an active boycott as a means of establishing the political independence of the working class.

The Brexit referendum is a product of the deepening antagonisms produced by the drive of the rival imperialist powers to dominate the world’s markets and strategic resources. It is this conflict that has fatally undermined all efforts to unify the continent economically and politically on the basis of capitalism. Unless the working class intervenes, this will end in the Balkanisation of Europe and a rapid descent into the conditions that gave rise to two world wars.

The crisis facing the bourgeoisie drives it to launch ever more brutal attacks on jobs, wages and social conditions, to move towards authoritarian forms of rule, and to engage in wars of colonial conquest that are opposed by millions. As is being proved in the eruption of opposition in Greece, Belgium and France, this creates the objective conditions for the emergence of a continent-wide social and political struggle against capitalism.

The task placed before workers and young people is not to build new borders, but to tear them down; to replace the bosses’ EU with the rule of the working class in a United Socialist States of Europe. For this reason, the stand taken by the SEP is of historic significance. It points a way forward not only for workers in the UK, but throughout Europe.