Vladimir Franz, an opera composer and painter, is tattooed from head to toe, his face a warrior-like mix of blue, green and red. He's also running in a surprising third place ahead of this week's Czech presidential elections.

He seems the most unlikely of candidates for a prestigious post previously held by the beloved dissident playwright Václav Havel and by Václav Klaus, a professor credited with plotting the economic transition from communism to a free market.

During a televised debate, a caller compared him to "an exotic creature from Papua New Guinea". But he's not short of admirers in a country where voters are increasingly tired of politicians they say are corrupt and failing to deliver on years of promises, more than two decades after the fall of communism.

Franz has no political experience and confesses to little knowledge of economics. He says he only threw his hat in the ring after a group of admirers established a "Franz for President" initiative and begged him to shake up the race as a shock candidate. But he has stirred up such goodwill that a leading economist has offered his services for free and his campaign workers are also volunteers.

He has spent less than £16,000 from donations on his campaign and has not put up any posters.

Franz burst on to the political scene at the end of 2012 with an eye-catching 88,000 public signatures in favour of his candidacy – far more than the 50,000 required by law. Not affiliated with any party, he has campaigned mostly on a platform highlighting anti-corruption measures, the importance of education and the nation's moral standing.

"The [political] system is so enchanted with itself that it's lost the ability to self-reflect," he said in an interview with AP this week. Czechs, he said, were "fed up with this crap."

He has proved particularly popular with young voters – and those not yet eligible to cast a ballot. In a mock presidential election at 441 high schools across the country a month before the vote, Franz won by a landslide, winning more than 40% of the approximately 60,000 votes cast.

He is tipped to win around 11% in the first round on Friday and Saturday – not enough to make the runoffs. But he may end up a kingmaker, as the leading candidates – former prime ministers Jan Fischer and Milos Zeman – would be eager to pick up his supporters if the vote goes to a second round.

Education campaigner Karel Strachota, who organised the school ballot, said young people no longer identified with existing parties. Franz is seen as "a candidate who is not tainted by politics," Strachota said. "They look with sympathy at his nonconformity and the way he presents himself."

And, perhaps surprisingly, few take issue with his tattoos. "Personally, I wouldn't vote for him – but [the tattoos] are not a problem at all," said Tomas Pistora, a 33-year-old IT specialist from Prague. "The young people prefer him because they don't have a better choice."

Many Czechs, especially in the capital, are not shocked with Franz's appearance simply because the 53-year-old professor at Prague's Academy of Performing Arts has been around for years.

"The tattoo doesn't make any difference," said Jakub Fisera, a student in Prague, adding that Franz's lack of experience in politics was more of a problem.

Franz says his tattoos are simply body art and that the election is not a beauty contest. "A tattoo is a sign of a free will and that does not harm the freedom of anyone else," he said.

For the first time, the Czech president will be elected in a popular vote – a new system that makes it possible for independent candidates like Franz to run for the largely ceremonial post.

Klaus, the incumbent, opposed the change. He called it "a fatal mistake" and said he feared that someone like Franz might succeed him.

A total of nine candidates are running. Unlike the Eurosceptic Klaus, who has attacked the European Union at every opportunity, the favourites, Zeman and Fischer, have a more moderate approach to the EU, which the country joined in 2004.

The left-of-centre Zeman, who was prime minister from 1998 to 2002, leads the polls with about 25% support. Fischer, a centrist and a former state bureaucrat, gained significant popularity when he led a caretaker government in 2009-10. He is polling at about 20%.

As the campaign approached its end on Tuesday, eight candidates were busy on the stump. The ninth – Franz – had other matters to deal with: a final rehearsal of his work War with the Newts at the State Opera. Torn between art and politics, Franz cut short his appearance at an election debate to return to the opera house that is part of Prague's national theatre.

But he has committed to staying to the end of Thursday's final televised debate. He said it was not an easy choice, but he realised his credibility demanded that he take part.

"For a Czech composer to have a world premiere in the national theatre is something extraordinary," he said. "I had to make a choice between a service to the public and the fulfilment of my lifelong dream. I've made the choice and will be at the debate."