It’s quite a charge sheet. Jiri Drahos, the pro-Western liberal running to be the next president of the Czech Republic is accused of being a pedophile and a Communist-era secret police informer who risks turning the country into an Islamic state because he wants to let in a flood of Muslim migrants.

That is the narrative pro-Kremlin Czech websites have been spinning for voters as they prepare to cast ballots this weekend in the final round of the presidential elections.

The Czech Republic is no stranger to fake news. But these elections have released a new wave of disinformation, as the pro-Russian incumbent, President Milos Zeman, fights off a determined challenge from Drahos. The latest opinion polls show he even has a slight lead.

Though the presidency is a largely ceremonial post, whoever wins could have decisive influence right now as the government is mired in crisis — one reason many believe the pro-Kremlin information machine has been so active.

Supporters of Drahos say his comments have been twisted into statements depicting him as supporting illegal immigration and Islamic dictatorship. This is despite the fact that he has said he opposes European Union quotas mandating that each member state resettle a certain number of refugees.

“A vote for Drahos would mean silencing patriots, civil war and the invasion of hundreds of thousands of Muslims!” screamed one headline on the conspiratorial “Svobodné noviny” (Free News), which was then picked up and repeated on other sites.

To underline the charge, Zeman’s advisers placed an inflammatory advertisement (see picture above) in major Czech newspapers just a few days before the vote. Flanked by a picture of the sitting president are the words: “Stop immigrants and Drahos — this country is ours! Vote Zeman!”

In a series of identical Facebook posts, Drahos was also dubbed a thief, a Freemason, a “sexual deviant” and a pedophile — attacks that were then taken up by “Parlamentní listy,” a Breitbart-style website that researchers have noted has “strong links” to Milos Zeman. The headline on one article read: “How’s your pedophilia, Mr. Drahos?”

It is hard to work out exactly who is behind all this. The newspaper advertisement was booked by the Friends of Milos Zeman, an organization led by two of the president’s closest advisers.

But it is impossible to find out who is ultimately paying, according to Czech investigative journalist Ondrej Kundra, because they use legal loopholes to mask their donors. “They run it to his [Zeman’s] advantage and send him millions,” wrote Kundra in Respekt, a Czech weekly, “but they refuse to say where the money came from.”

Some suspect a Russian hand, but no one has come up with proof. Whatever the case, it has made it much easier to run what critics have called a “dirty campaign” against Drahos.

This comes as the Czech government is in turmoil. Andrej Babis, the newly-elected Prime Minister, and a Zeman supporter, is mired in scandal because of fraud allegations, and recently lost a vote of confidence — and with it his parliamentary immunity.

But Zeman is a divisive figure too, with a record of pushing the constitutional limits of his nominally-ceremonial position. So his opponents are concerned his re-election would give him undue influence over the government. And even if he loses, he has vowed to re-appoint Babis — because he would not have to step down until the next presidential term begins in March. Critics fear a Zeman victory could also lead to the country moving closer into Russia’s embrace, despite the fact that only a minority of Czechs support such a move.

Drahos has fought back, rejecting claims that he collaborated with the country’s Communist-era secret police, the StB. He published copies of his “lustration” certificate clearing him of the charge, as well as an official statement from the government agency overseeing Communist archives.

His supporters have joined in the battle online. One group set up a website to rebut the fake claims being spread about Drahos called PoPravdě.cz (“In Truth”), after the first round of the elections. The group’s spokesperson, Pavel Bartos, said they have been attracting hundreds of thousands of visitors.

But he is concerned such efforts may have come too late. In an email, Bartos noted how Zeman first won the presidency five years ago after a campaign infused with falsehoods. The same could happen again, he said: “There are many signals that [Czech voters] will be affected by this disinformation campaign.”

There has also been little visible activity from the country’s so-called “fake news center,” a government agency launched with much fanfare last year in an effort to combat disinformation. It has only tweeted two comments on false claims since the election campaign got underway. Nonetheless, the center’s supporters insist it is doing important work behind closed doors.

One thing that has changed since the last presidential election is that voters are far more aware of fake news as a phenomenon — so it could also work against those who have been spreading it. So the result of this weekend’s vote will not just be a verdict on the candidates, but on the power of disinformation.