The populist is known for his fierce rhetoric on European immigration and support of Russia and is seen as a “marmite figure” in the Czech Republic.
Mr Zeman is expected get the most votes in the first round with the latest public poll by TNS Kantar & Median suggesting he will take 42.5 percent of the vote.
His nearest rival, Jiří Drahoš – the pro-EU former head of the Czech Academy of Sciences – scored 27.5 percent.
The most recent public poll of the second round of votes had Mr Drahoš pipping Mr Zeman to the lead with 48.5 percent of the vote, while the existing president scored 44 percent.
Emily Mansfield, Europe analyst at the Economist Intelligence Unit (EIU), said this would be a direct backlash to the first result and described Mr Zeman as being a “marmite” candidate with Czech voters.
“You either love him or hate him,” she told Express.co.uk.
Miloš Zeman is tipped to win the Czech election 2018 ahead of rival Jiří Drahoš
She said the controversial leader had “courted controversy” attracting a wide pool of candidates but Mr Drahoš’s campaigning had been somewhat lacklustre.
She added: “Mr Drahoš has run a fairly bland campaign; like the other liberal candidates, he proposes to be a more statesman-like president, stresses his commitment to liberal democracy and the Czech Republic’s Western orientation, and relies heavily on the anti-Zeman vote.”
Dr Jan Culik, senior lecturer in Czech at the University of Glasgow, said the overall situation is “uncertain” although there is a “large cohort” of the public backing Mr Zehman.
He said: “Zeman´s supporters are united while those voters who are against Zeman are totally disunited and seem to support a number of different candidates.
He is a man who fights for our national interests
“There is a possibility that Zeman might win the first round outright.
“However, if he does not do so, there is at least one opinion poll which says that Drahos would win over Zeman in the second round.
“The situation is unclear, apart from the fact that there is a large cohort amongst the Czech voters who will support Zeman.”
Mr Zeman has promised to back Czech Prime Minister Andrej Babiš’ minority ANO government, which is facing a crisis after other parties refused to work with it.
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Czech Prime Minister Andrej Babiš has publicly backed Miloš as his preferred candidate, praising the firebrand for his honesty and populism.
Mr Babis said: “I see him as a strong personality which is polarising society, but mainly as someone who does not steal, who has results, who keeps his word… and unlike other politicians, he does not live from politics, he lives for politics.
“He is a man who fights for our national interests, he is not afraid to clearly state his opinion on Brussels, (migration) quotas, he fights for the interests of our entrepreneurs.”
Miloš Zeman is backed in the Czech election 2018 by Vladimir Putin
When is the Czech election 2018?
The presidential election is being held over Friday January 12 and Saturday January 13 in the Czech Republic.
If no candidate wins majority in this round of the election, there will be a run-off between the top two candidates on January 26 and 27.