Penetrating deep into the country’s vast interior on epic raids for people to enslave and mineral wealth to plunder, Brazil’s bandeirantes massively expanded the frontiers of the young state in the 16th and 17th centuries.

Today the legacy of these pioneers remains divisive, but their profound contribution to both Brazil’s continental dimensions and history of violence remains indisputable. And for the members of the libertarian Movimento Brasil Livre (MBL), or Free Brazil Movement, the legend of the bandeirantes is a political inspiration.

“They were self-made men from São Paulo, and they turned Brazil into the biggest country in Latin America,” said Renan Santos, the MBL’s national coordinator. “For sure, they were not a great example in terms of human rights.”

On Friday afternoon, Santos and a few dozen other activists will set off from the Praça Panamericana in western São Paulo on a 1,000km (621-mile) walk to Brasília, the Brazilian capital, following one of the routes of the bandeirantes.

Along the way, they will pass through towns and cities spreading the gospel of economic liberalism. And when they finally arrive in Brasília, they plan to hold a mass rally and present a simple message to congress: impeach President Dilma Rousseff.

“It’ll be a journey,” said Santos, 31. “Like Lord of the Rings.”

Since the president’s narrow re-election in October 2014, various activist groups have sprung up across Brazil to protest against the government over a massive corruption scandal at the state-run oil company, Petrobras.

Some organisations, like Vem Pra Rua, have links with the country’s main political opposition and business elite. Others, like Revoltados Online, are more traditionally rightwing, with T-shirts bearing the slogan “God, Family and Freedom”. There are even some fringe organisations, like SOS Forças Armadas, demanding outright military intervention.

“Vem Pra Rua and Movimento Brasil Livre are the two most significant groups,” Esther Solano, a professor of international relations at the Federal University of São Paulo who has studied the protesters, said. “Vem Pra Rua tends to attract an older, more political crowd, whereas Movimento Brasil Livre brings together younger, more apolitical protesters.”

An opinion poll published last week showed 63% of Brazilians would support impeachment proceedings against Rousseff, though the survey also revealed deep ignorance about what that would mean.

Though the MBL’s main demand is impeachment, it distinguishes itself from the other protest groups by claiming to offer the ultimate solution to Brazil’s corruption problems: economic freedom.

Anti-government protest leader Kim Kataguiri poses in São Paulo, Brazil. Photograph: Andre Penner/AP

“We defend free markets, lower taxes and the privatisation of all public companies,” Kim Kataguiri, 19, one of the MBL’s founders, said. Kataguiri, who became famous after posting a series of lectures on YouTube, argues that the first step to fulfilling this dream must be the removal of Rousseff, of the Workers’ Party (PT), over her failure to stop the corruption at Petrobras.

Kataguiri, like Santos, is a university dropout who has dedicated himself to spreading the message of the Austrian School of Economics in a country that has an overwhelmingly statist approach to economic policy-making. A fan of Milton Friedman and Friedrich Hayek, Kataguiri also speaks excellent English that he learned “from video games”. He describes Margaret Thatcher as a reference point for his movement and Rand Paul as the US politician who best represents his values.

“In Brazil, the left is still seen as cool by young people,” he said. “We want to destroy this idea that if you defend free markets then you’re an old man who is asking for a dictatorship.”

A few days before the march, the atmosphere in the MBL’s São Paulo office is more hipster startup than Frodo’s shire.

Half a dozen young activists sit around a large black conference table, poring over their laptops as they attempt to finalise the route, secure provisions and mobilise their supporters.

The son of a metal worker from the interior of the state, Kataguiri denied claims the MBL had any wealthy backers, stating that it raised money from donations and selling T-shirts and stickers.

“Unfortunately, we don’t have any big sponsors,” he said. “The government and some sectors of the press say that we are financed by rich people. We would have no problem in being financed by rich people.”

Unlike the other major protest group, Vem Pra Rua, the Free Brazil Movement has little contact with the main opposition Brazilian Social Democracy Party (PSDB).

The MBL convoy plans to reach Brasília on 27 May, after a 33-day hike through the states of São Paulo, Minas Gerais and Goiás. The group then hopes to rally 100,000 Brazilians to demand congress begin the president’s impeachment.

“If they don’t accept our demand, we will have to choose,” Santos said. “We can choose to go home or we can choose the Ukrainian way. We are not talking about violence, but maybe occupation. We are talking about keeping up the pressure.”

But for Professor Solano, the wave of public anger that fuelled the recent protests may be starting to diminish.

“The last demonstration against the government [on 12 April] only attracted significant numbers in São Paulo,” she said. “Elsewhere, there were hardly any demonstrations. Now political leaders from the main parties are speaking out against impeachment, pointing out there is no legal basis.”

Kataguiri and Santos, however, believe the momentum is still with them. “We’ve been doing crazy things from the start,” Kataguiri said. “We have the will to take our message to Brasília.”