There's a new revolutionary force in Belgian politics, and its lodestar is a 19th-century German Jew named Karl Marx.

The Belgian Workers' Party, or PTB, is charging traditional parties from the left, threatening the once-almighty Socialist Party and disrupting the country's politics that, until today, were drifting slowly to the right.

With a rebooted Marxist platform, the PTB has gained momentum in Belgium's fractious political landscape, in large part by campaigning against globalization. Its rise comes at the expense of the Socialists and causes particular pain for Paul Magnette, minister-president of the Walloon region, as well as party chairman and former Prime Minister Elio Di Rupo.

The PTB had their international coming out this fall. When the landmark trade deal between the EU and Canada was blocked, the public face of its adversary was Magnette. But close observers credited the Workers' Party with pushing the high-profile trade deal known as the Comprehensive Economic and Trade Agreement — and possibly the EU's entire trade agenda — to the brink of death.

Dave Sinardet, a professor of political science at the Free University of Brussels, is among those who argue that it was pressure from the Workers' Party that forced the Socialists to block the trade deal in October, before relenting. "The whole CETA tale ... was largely strategic, because of the pressure of the PTB," he says.

Stealing from left, give to far left

The PTB was founded in the 1960s as an orthodox alternative to the Belgian Communist Party, which was seen as going wet then. It stayed on the margins for decades, before creeping onto the political scene of late.

"The Socialist Party is seen as less credible by a lot of left-wing voters" — Dave Sinardet, professor of political science at the Free University of Brussels

Two years ago, the party got its first two representatives elected to the federal parliament and, since then, the party has gained significant support -- especially in the depressed industrial region of Wallonia where it was polling at 18.4 percent this month, within striking distance of the French-speaking Socialists (PS) at 25.4 percent and Prime Minister Charles Michel's Liberal Reformist Movement at 23.1 percent.

Elsewhere, it's had trouble breaking through. In Brussels, PTB polls at 9.6 percent. Despite some success in smaller constituencies in Flanders, the PTB appears blocked at 5 percent — the electoral threshold for getting seats in federal or regional parliaments — in Belgium's northern, more nationalistically minded and right-leaning region.

In a country known for its progressive welfare system and high standards of education and health care, a party nibbling at the heels of the left from the left may seem odd. And yet, the PTB platform against social inequality has clearly connected with voters in Wallonia where the Socialists have previously been unrivaled.

Its crusade against fat salaries for CEOs of state-owned companies in conjunction with its staunch defense of pensions and unemployment benefits have caught the attention of voters disenchanted with more mainstream left-wing parties.

When the American company Caterpillar announced the closure of a factory near Charleroi this summer, costing as many as 6,000 jobs in the region, the Socialist Party tried to negotiate with the U.S. giant while the PTB joined trade unions in protests over the job losses.

"The Socialist Party is seen as less credible by a lot of left-wing voters," says Sinardet. "Di Rupo had to make a whole lot of concessions [during his time as prime minister, 2011-2014]. He still carries that burden."

'The Lionel Messi of the PTB'

The party's hopes are pinned on a young, rising star named Raoul Hedebouw. His party chairman, Peter Mertens, calls him "the Lionel Messi of the PTB."

Hedebouw, 39, joined the party as a teenager almost 20 years ago. His parents were steel workers, giving him the class credentials to act as the spokesperson for his party -- something he has done eloquently, often challenging the country's most veteran politicians to debate. He speaks in football metaphors, invoking his upbringing in a workers' family. He says he gives half his parliamentarian's paycheck to the party because he "only needs half anyway," adding that "I live like a normal person."

A biologist by training, Hedebouw started his political career organizing high-school student protests. He still appears fresh-faced and is prone to frequent smiles.

"I'm part of a generation that only ever really knew four parties," he says in an interview. "Now, a fifth party is breaking through -- it's causing a remaking of the political landscape."

Raised in the Walloon city of Liège by Flemish parents who spoke Dutch, he is one of the few politicians in the linguistically divided country who can pull off appearances on both French and Dutch TV without looking awkward.

"He's no-nonsense," says Sinardet. "He speaks a language people can understand and succeeds in conveying a certain indignation."

Hedebouw's mastery of the country's two main languages fits the PTB's profile.

For decades, Belgian politics have been divided by language. The Socialist Party, the Liberals and the centrist Christian-Democrats all split into Flemish and French-speaking parties in the late 1960s and 70s. The Workers' Party is the only party in Belgium that contests for seats across the country's linguistic borders.

That appeals to voters frustrated by the Balkanization of Belgium, where more decisions are taken at the regional level. The three communities -- Dutch-speaking, French-speaking and German-speaking -- oversee culture and education, while the regions -- Flanders, Wallonia and Brussels -- deal with the economy, employment, housing, transport, urban planning and even foreign trade.

Many Belgians, however, feel it's time for a change and that the decentralization may have gone too far.

Contemporary Marxism

In the past, the PTB has supported the Soviet Union and Beijing and even maintained loose ties to the North Korean regime. But the party underwent a transformation in 2008, curbing its hard-left flank to appeal to a broader range of voters.

The party's core platform still builds on classic leftist issues like abolishing the wealth gap, a crackdown on tax evasion and free, fully subsidized education and health care.

The party has been building networks across the Continent, establishing ties with the Dutch Socialist Party, Die Linke in Germany and Syriza in Greece, among others.

"Belgium has a tax policy of two speeds," says Hedebouw. "Citizens pay too much tax while big companies pay close to none."

It's added the fight against climate change and furthering sustainability to its platform in recent years as well.

"Contemporary Marxism," is how Mertens describes it.

The reinvented PTB now resembles other leftist movements across Europe. The party has been building networks across the Continent, establishing ties with the Dutch Socialist Party, Die Linke in Germany and Syriza in Greece, among others.

The PTB doesn't have an elected official at the European level. But they have an observer in the European Parliament's far-left GUE-NGL group that allows them to be in the political loop.

When it comes to the EU, the party doesn't aim to scrap the Union or "drain the swamp" like some parties on the far right. But it is vehemently opposed to the EU's centrist coalition which, it says, prevents real change.

For now, the party seems happy to serve as the bête noire of the Socialists in southern Belgium and winning strategic victories such as the blocking of CETA by dragging their left-wing rivals further left.

The Socialists have spent 25 years in government and had their chance to change the course of the country but they didn't do that, says Mertens, the 47-year-old party chairman, who also got his start in student politics, serving for a while as the head of the Marxist-Leninist Movement. "Under pressure from a PTB on the rise, I see them taking leftist positions," he says. "I'm very glad about that."