TODAY Belgium will grind to a halt. A general strike supported by the three main trade union confederations is expected to paralyse transport across the country.

Organisers expect 100,000 people to demonstrate on the streets of Brussels. Given the population disparity — Belgium has about one-sixth the population of Britain — this is equivalent to the very largest of the Palestine demonstrations of recent years, but this is specifically a mobilisation of organised labour, aimed at blocking the Bart de Wever government’s attacks on wages, pensions and social security.

And it’s not the first. Belgian Workers Party Peter Mertens, who met me in the Marx Memorial Library a week before the demo, points out that this is the 15th such mobilisation in the last 16 months. Belgium is gripped by a protracted struggle between capital and labour, over “reforms” that weaken workers and strengthen employers.

“They want to reform pensions so if you leave your job before you turn 67, the pension can be reduced by up to 20 per cent. This hits women hardest because they are less likely to have had full-time careers.

“They promised that there would be exemptions for what they called ‘heavy’ jobs, but didn’t keep their promise, so construction workers are very angry.

“It’s also about salaries.” In Belgium, over 80 per cent of workers are covered by collective agreements and wages are indexed to inflation in most sectors. But the government is seeking exemptions to this rule to cut business costs — “even in those industries making record profits.”

The erosion of terms won by workers to compensate for working anti-social hours — which also disincentivise employers from trying to make people work such hours, or on public holidays and so serve a wider social purpose — is part of its plans too.

An example Mertens gives is that night shifts, which pay a premium by law, are being redefined so only hours between midnight and 4am, rather than 10pm and 6am, count — “so you get four hours rather than eight” (at the higher rate of pay).

“It’s 50-50 now” (the balance of forces). “They didn’t get the plans through parliament; but they didn’t retreat either. It’s unclear at the moment who is going to win.”

There is a different, more militant mood among Belgian unions, he says. “It’s not an everyday movement. Fifteen demonstrations on this scale in 16 months. And the first took place even before the government was in place” (Belgian elections do not produce majorities, and it took eight months from the 2024 election before a coalition government was stitched together).

“On the first day of the new government there were 100,000 protesting — that’s new. The mood used to be ‘give the government a chance’ — now it was we shouldn’t give them any chance at all.”

If that sounds unreasonable, perhaps we in Britain have got too used to reacting to ruling-class attacks rather than getting our own demands onto the national agenda first. Belgium’s unions knew the government would come for pay, pensions and conditions, and they made the scale of their opposition clear immediately.

The movement unites Belgium’s three main union confederations (Christian Democrat, Social Democrat and Liberal), private and public-sector workers, “north and south, both languages” (Belgium divides into two main communities, Flemish-speaking Flanders and French-speaking Wallonia, with their own parliaments and often divergent politics).

Unions are waking up too, he says, to the connection between cuts to pay and services and the Europe-wide militarisation drive.

“There is austerity in every department in Belgium except defence. They want to take billions from the pensions system and education for the €34 billion (£29.4bn) they have earmarked for defence in the next few years.”

The Workers Party of Belgium is a success story among modern European communist parties, having grown from a small sect to a party with MPs, MEPs and a high profile across Belgium’s three regions (Brussels is governed separately from Flanders and Wallonia). In Brussels it is the largest party, polling at about 25 per cent; its national polling is about 11-12 per cent.

It attributes its success to a relentless focus on organising within the trade unions and backing workers in disputes as well as a refusal to budge from the essential tenets of Marxism-Leninism.

The original divide between what became known as communism and social democracy grew out of different reactions to war: most parties of the Second International supported their respective ruling classes’ war efforts during World War I, with anti-war figures like Lenin and Rosa Luxemburg facing initial isolation.

So it is no surprise that Europe’s militarisation is a big concern for Mertens. And, over years of hard work, he says Workers Party cadres have turned it into a major concern of the trade union movement too.

Both the social democrat and Christian democrat union federations have joined the Stop Militarisation coalition, alongside a number of parties and community organisations. The coalition’s manifesto states: “War is terrible and the search for solutions is essential. The current Belgian government has only one approach: more weapons and more military spending. However, history shows that this does not lead to peace, nor does it guarantee ‘security’.”

Peace is not the main theme of today’s demonstration, but a more specifically Welfare Not Warfare mobilisation will take place in Belgium on June 14.

The anti-war struggle is international too, and he intends to be at the International Anti-War Conference in London on June 20 — “see you there,” are his parting words as he heads off with a comrade to watch an Arsenal game.

That drive to war is down to the inability of the traditional capitalist “core” in Europe and America to maintain living standards or control of the “periphery” — a key theme in Mertens’s influential book Mutiny.

He has written another on the scale of the global changes coming our way — The Last Days of the Old Normal — and was in London partly to find an English-language publisher.

Knowing Mertens, it will be worth a read.