PRAGUE (Reuters) -Czech billionaire and ex-prime minister Andrej Babis looks set to win this week's national vote, but may need to navigate a fraud trial as well as anti-EU and anti-NATO demands from allies and calls to divest from his businesses in a return to power.

The Babis-founded ANO party is leading opinion polls before the October 3-4 election, with promises to shower voters with money and shield them from dangers outside Czech borders, such as costly climate policies or immigration.

Babis, a 71-year-old Slovak-born businessman, has turned from liberal to national conservative positions since entering politics in 2011 and running a centre-left cabinet in 2017-2021.

ANO will almost certainly fall short of a majority, posing a challenge for the combative Babis, whose core strategy of accusing mainstream parties of corruption has left him with few allies.

WALKING A TIGHTROPE

The animosity will likely push Babis to seek support, perhaps for a minority cabinet, from the far-right SPD and possibly the far-left Stacilo!, which both want to quit the European Union and NATO and halt aid to Ukraine.

Walking a tightrope between pandering the political fringes, and staying on a broadly pro-Western course, Babis has been blasting the EU - but also making clear he would not allow any steps toward exit.

"The EU comes up with regulations, snooping, green taxes, but we must win against that in the European Parliament," Babis told a rally in the central town of Kralupy on Monday, calling to "rout the green madmen, people's party and socialists who do all they can to destroy Europe."

The crux of his view is that the EU should be run exclusively by national leaders and not institutions like the European Commission.

But maintaining such a strategy towards the EU will be tough with extremist allies and a fragmented parliament, political analyst Lukas Jelinek said.

"SPD and Stacilo! will not sell their skin cheap," Jelinek said. "It would be a surprise if Babis manages to put together a minority cabinet that would last all four years."

STRONG RELATIONSHIP WITH ORBAN

Babis once wanted to join the euro but has since become a eurosceptic and a Trump supporter, handing out "Strong Czechia" baseball caps inspired by Trump's MAGA slogan.

Still, Babis refuses Trump-backed NATO defence spending targets, and has criticised tariffs and failure to reach peace in Ukraine.

Babis has no allegiance to ideology, but values personal relationships. A prominent one is with Hungarian leader Viktor Orban, whom he joined to form the anti-Brussels Patriots for Europe in European Parliament.

"There is a strong personal relationship and certain admiration for how long, and how strong, Orban has held power in Hungary, and how he is -- however unconstructively -- able to play a role in European matters," said Tomas Petricek, a former foreign minister in Babis's cabinet.

EU SUBSIDIES, FRAUD CASE

Babis was born to a diplomat under communist rule, attending secondary school -- and playing volleyball -- in Switzerland. He joined the Communist Party, worked in foreign trade and had contacts with the secret police.

After communist rule ended in 1989, he set up Agrofert, gradually building it into an international food and chemicals conglomerate with 30,000 employees.

Agrofert became intertwined with the state through public contracts, and farming and development subsidies. It received 1.6 billion crowns ($77.21 million) last year, mainly European Union direct payments for farm production.

Under Czech and European conflict of interest rules, Babis must sell his firm, or the company must stop drawing subsidies, or he must stay out of the cabinet and nominate a deputy to lead it, watchdog Transparency International said.

Last time in government, Babis put Agrofert in trust funds but experts say that is no longer an option after EU and local rulings.

As ANO's candidate for prime minister, Babis, who is worth $4.3 billion according to Forbes magazine, says he will respect the rules - but also not sell Agrofert.

Transparency International's Czech director David Kotora said Babis's intentions were not clear.

"We can get into a situation we have had in 2017-2021 ... when he tried to delay, trivialise the issue through institutions that ANO controlled," he said.

Failure to resolve the conflict could spark action by the European Commission to halt subsidies for Agrofert, he said.

Babis also faces a rerun of a trial, after an appeals court overturned an acquittal, over allegations he committed fraud in tapping a 2 million euro EU subsidy to build Capi Hnizdo, a conference centre near Prague.

Babis denies wrongdoing and calls the case political.

Babis was stripped of his parliamentary immunity in the outgoing parliament, allowing prosecution to go ahead. But his immunity will be restored in the election and he might forestall the trial if he could convince the new parliament not to remove it this time.

($1 = 20.7220 Czech crowns)