Visitors to Budapest in recent weeks may have noticed the proliferation of a strange three-character code all across the city: “O1G”.

Graffitied on to walls and fences: O1G. Traced into the snow on car windscreens every time a wintry flurry falls: O1G. The abbreviation is short for Orbán egy geci, a pithy phrase deriding the prime minister, Viktor Orbán, using a Hungarian expletive that literally means sperm but is used as a catch-all insult.

The code has been adopted by anti-government protesters who have been holding demonstrations for the past six weeks against Orbán’s nativist government, accusing Orbán of increasing authoritarianism and a crackdown on the media. Causing particular anger is a so-called “slave law” that increases the overtime employers can demand from workers and allows them to delay pay for up to three years.

With the exception of a few scuffles, neither side has shown any appetite for violence. Orbán, whose Fidesz party won a third successive term in office last April on a far-right anti-migration platform, appears secure. But the rhetorical aggression is certainly rising.

At the latest anti-government protest, held by the Danube in central Budapest on Saturday, those in attendance could purchase slices of bread with O1G drawn on in blood-red spicy paprika paste. Later in the evening, a group of women were scrawling O1G repeatedly in chalk on the tiled walls of the 1850s tunnel that runs underneath Buda Castle.

Facebook Twitter Pinterest A dog sports a badge with the O1G code at an anti-government protest in Budapest. Photograph: László Balogh/Getty Images

Hungarian politics has hardly been a place of polite decorum for some time. For a number of years, government-linked media outlets have spewed out a diet of hatred and fear-mongering when it comes to migrants and refugees. Orbán’s media machine has painted opposition politicians and other critics as anti-patriotic puppets of the billionaire George Soros.

A recent questionnaire on the Hungarian website 444.hu offered readers a series of quotes and invited them to guess if they were from Hungarian media outlets talking about migrants, or from Radio Rwanda on the eve of the country’s genocide in the 1990s. With Hungarian examples referencing “filthy rats” and “inevitable bloodshed”, it was difficult to correctly guess which quote was from which country.

Perhaps the most illustrative example of the recent escalation in the war of words is the case of Blanka Nagy, a 19-year-old in her final year of high school in the town of Kiskunfélegyháza. A speech she gave from the stage to a small crowd at a December protest in the town of Kecskemét went viral recently, a month after the event.

“There is a disgusting, contagious epidemic in this country. It is not plague, Ebola or mad cow disease, though it is a bit similar to the latter. The name of this epidemic is Fidesz,” she said in the video. She also referred to the president, János Áder, an Orbán ally, as “the dick with the moustache”.

In response, government-linked media have gone on the offensive, launching deeply personal attacks on Nagy over the past week. “Dear Blanka! The thing is that you are not a hero but a miserable, wretched, vile little prole,” said Zsolt Bayer, a controversial pro-Orbán television host.

“Those who speak like street hookers should not be surprised at being talked to like street hookers,” wrote András Bencsik, the editor of the pro-government magazine Demokrata, in a Facebook post he later deleted. Other outlets have questioned her grades and insinuated she could be kicked out of school.

“It was strange to wake up one day and see my face all over the internet, but it hasn’t affected me negatively. A lot of people have stopped me in the street to offer their support,” said Nagy, who spoke at Saturday’s protest in Budapest.

“It expresses an increasing frustration. The biggest fear of authoritarian politicians is being ridiculed, and they can’t handle it,” said Péter Krekó, a Budapest-based political analyst.

The most recent protests have been different to previous rounds of anti-Orbán demonstrations over the years, gaining traction in smaller towns as well as among Budapest liberals. Opposition figures hope anger over the slave law could galvanise a broader spectrum of protesters. However, plans for a general strike look unlikely to succeed, and there is little sense of what the end goal of the protests may be.

At this weekend’s rally in Budapest, the crowd of a few thousand was less than those in December, and already there was a sense that the protest mood could be beginning to drift. One speaker attempted to get a chant of “We are not going home” going in the crowd, but the response was half-hearted.

Nagy admitted that among her generation, there were few politically active individuals but said she had hope that the protests would achieve some kind of change, starting with the European parliament elections in May.

“There are many options. More and more towns are getting involved. Hopefully we’ll see the opposition do much better at the European elections.”