Fervent in his opposition to abortion and gay rights, as well as support for gun ownership and an aggressive military, the congressman is Brazil’s version of nationalist, conservative politicians gaining prominence around the world.

Opponents condemn Bolsonaro as racist, homophobic and an apologist for torture during the two decades long military dictatorship that ended in Brazil in 1985.

However, the 62-year-old is no fringe politician. With Brazil mired in problems, his message of toughness and an end to business as usual is striking a chord.

He won more votes than any other congressman from Rio de Janeiro state in the last general elections in 2014.

And after steadily rising in opinion polls, he now lies tied in second place for the presidency in 2018, behind leftist former two term president Luiz Inacio Lula da Silva.

A big selling point for Bolsonaro is that he’s one of the few top politicians in Brazil not to have been accused of corruption in the “Car Wash” anti-graft investigation.

To name just two high-profile targets, current center-right President Michel Temer faces a bribery charge, while Lula has been convicted of bribe taking and faces multiple trials.

Last week, Congress voted overwhelmingly to spare Temer from having to go to trial, adding to public disgust. Bolsonaro, one of the congress members who voted against Temer, called corruption Brazil’s “cancer.”

While a longtime congressman is hardly a political outsider, Bolsonaro has succeeded in painting himself as someone “outside the traditional political elite,” said David Fleischer, professor emeritus at Brasilia University.

Opponents describe Bolsonaro’s radical positions as a danger to democracy.

He drew gasps from many in Brazil last year when he voted to remove leftist president Dilma Rousseff from office in an impeachment procedure and dedicated the vote to a notorious colonel from the dictatorship in which Rousseff was herself tortured.

“The terror of Dilma Rousseff,” Bolsonaro crowed on the floor of the House.

His outbursts also include telling a leftist congresswoman that she did not “deserve” to be raped and proclaiming he’d rather his son be killed than gay.

But on Thursday he only revelled in his reputation.

“I’m not the ugly duckling - I’m the horrible duckling,” he joked.

Lula leads in all scenarios for 2018, according to a June poll by the respected Datafolha institute, with Bolsonaro and former 2014 presidential candidate, the environmentalist Marina Silva, coming second equal.

Although Lula is ahead, he has by far the highest rejection rate at 46 per cent and in any case may be barred from running because of his bribery conviction.

For all his incendiary remarks, Bolsonaro’s own rejection rating is 30 per cent.

It’s still far too early to make predictions about the elections. The country’s division between extremes of Lula on the left and Bolsonaro on the right partly reflects the fact that a convincing centrist has yet to take up the challenge.

What’s sure is that Bolsonaro is serious, managing to mix his extreme comments with a “mellow and laid back” style that ordinary voters like, Fleischer said.

“He has a good delivery, a good art of conversation with people,” Fleischer said.

One sign of that popular touch? His Facebook page has over 4.5 million likes, far more than Lula’s three million and Silva’s 2.3 million.

And on Thursday he announced plans to change his awkwardly - and rather bizarrely - named National Ecological Party to something much more catchy: the Patriota party.