Petro Poroshenko has faced down protesters and rivals to lead the opinion polls before the first round of voting on Sunday

For a man with presidential ambitions, it was not a propitious scene. Petro Poroshenko stood atop a bulldozer between a line of police and an angry crowd chanting expletives at him. Shouting into a loudhailer he urged calm, asking protesters to desist from storming the presidential headquarters in Kiev.

Hardcore elements in the crowd didn't like his speech; they responded with jeers of "dickhead" and "Jew trash". (Actually, Poroshenko is a Christian.) Someone dragged him off his perch. Others managed to rescue him from this seething frontline. Masked youths grabbed the tractor and used it as a battering ram to force a path though police. Clouds of smoke billowed across Ukraine's warring capital.

This was early December. Six months later Poroshenko is on the brink of becoming Ukraine's new president. Opinion polls suggest he will win the first round of Sunday's presidential election by a landslide. Such is his lead he may even beat his nearest rival, former prime minister Yulia Tymoshenko, in the first round, avoiding the need for a run-off vote on 15 June.

For Poroshenko, it has been a steep rise to popularity that begs two questions: how has he managed it? And will this support help him accomplish one of the toughest jobs in the world today: running Ukraine?

Softly spoken, articulate, and fluent in English, Poroshenko bears little resemblance to the bear-like ousted president, Viktor Yanukovych. A former foreign minister and minister of trade, Poroshenko is no political newbie. But he has managed to dodge the unpopularity that has engulfed the rest of Ukraine's governing class.

Poroshenko's current popularity has much to do with adroit positioning. He wasn't one of the three opposition leaders – the current prime minister, Arseniy Yatsenyuk, boxer Vitali Klitschko and ultra-nationalist Oleh Tyahnybok – who signed a deal with Yanukovych. And his business fortune came not from the murky world of energy but from something altogether more palatable: chocolate.

"Poroshenko was on the Maidan [central square in Kiev]. But at the same time he escaped unpopular decisions," said Olexiy Haran, a professor of comparative politics in the capital. "He managed to present himself as balanced, reasonable and successful." Even when he popped up on Maidan, paying for food, water and firewood for protesters, he was careful to play both sides. "Russia isn't our opponent, but our partner," he told the liberal Moscow newspaper Novaya Gazeta. "Understand, Euro-Maidan is not a movement away from Russia, but from the Soviet Union."

Journey into politics



Born near Odessa, in south-west Ukraine, Poroshenko launched himself as a business consultant in the 1990s after studying economics in Kiev. (He met his wife, Maryna, a cardiologist, at a university disco; they have four children.) Poroshenko took over state confectionery plants and transformed them into a lucrative empire.

In 1998 he entered politics, winning a seat in Ukraine's lower house, the Verkhovna Rada, representing the Social Democrats. Two years later he founded his own Solidarity party.

Poroshenko's ambition quickly manifested itself, as did a political flexibility which strikes some as slippery. He co-founded the Party of Regions – the eastern-based party of Yanukovych. Soon afterwards, in 2002, he joined the Our Ukraine group of Yanukovych's pro-western rival Viktor Yushchenko. Poroshenko played a leading role in the Orange Revolution which prevented Yanukovych from fraudulently claiming victory in the 2004 presidential elections.

Yushchenko won a re-run vote, and Poroshenko became secretary to the council on national security and defence. He harboured hopes of becoming prime minister but instead the job went to Tymoshenko. Soon, though, this Orange coalition fell apart. Yushchenko fired Tymoshenko and Poroshenko, amid allegations of corruption, which he denied. Poroshenko remains close to Yushchenko, who is godfather to his daughters.

But after exiting government, Poroshenko bounced back. He served as foreign minister in 2009-10 and accepted an offer by Yanukovych – by this time president – to become minister of economic development. Poroshenko negotiated with the International Monetary Fund. Currently, he is an independent deputy without his own proper political party. (He has agreed an electoral pact with Klitschko's Udar party; Klitschko, the early front-runner, pulled out of the presidential race to support Poroshenko.)

According to Alexander Temerko, a London-based Russian businessman, Poroshenko is driven by deep religious convictions. He is a member of Ukraine's Orthodox church, and has financed the restoration of its buildings and monasteries. In high-level meetings he is often seen fiddling with a crucifix.

"Religion is important to many Ukrainians," Temerko said. "This gives him a fantastic advantage over other candidates, especially among simple people. Like Greece, Ukraine is a country of Christianity."

Following years of oligarchic misrule, does Ukraine really need another rich man in charge? "I think he has this feeling of public service in him," said Orysia Lutsevych, a research fellow with Chatham House's Russia and Eurasia programme. Lutsevych acknowledged that Poroshenko was wealthy, with his own business interests. But she added: "His business looks legitimate. It wasn't built on corrupt trade in gas and oil with Russia." Unlike other Ukrainian politicians "he was never involved in any big scandals".

Poroshenko made his own money – Forbes puts his net wealth at $1.3bn – from his chocolates, earning him the nickname of "the chocolate king". His other business interests include shipbuilding, construction and media.

What the future holds



So what would a Poroshenko presidency hold? A champion of European integration, Poroshenko is seen by many voters as the best person to reform the country's failing economy.

He can be under no illusions as to the grave challenges ahead. "If a country is to deal with Russia as an equal, it must be strong," he said last weekend. In the space of two breathless months, Russian president Vladimir Putin has annexed Crimea and fomented an armed uprising in the Russophone east and south. One of the Poroshenko's activists was brutally beaten up in Makiyivka, a town near Donetsk. In Luhansk, next to the Russian border, other members representing him on the local election commission were taken hostage.

After equivocating for weeks, the Donetsk-based oligarch Rinat Akhmetov has finally denounced the separatist uprising in the east. Still, not much voting will take place here on Sunday, with the possible exception of northern parts of Luhansk Oblast, under government control. Pro-Russian leaders have declared independence from Kiev, and have vowed not to recognise Sunday's elections. Masked gunmen are already seizing ballot boxes, including on Tuesday in the town of Artyomovsk.

On the campaign trail, Poroshenko has cast himself as the man who can rescue Ukraine from its numerous afflictions: break-up, corruption, a rampant shady economy and lousy governance. His long-term goal is to transform his nation of 46 million into a modern European state. He wants to decentralise power, amend the constitution and sign the latest chapter in the EU association deal, which he personally drafted as foreign minister. The European path will help Ukraine modernise, he argues, and – as his campaign slogan puts it – "to live in a new way".

But the spectre of a Yugoslav-style collapse remains. Poroshenko takes a hardline against pro-Moscow separatists. "What language do we have to speak with terrorists? That's right, the language of force," he told an election rally last week, according to the Kyiv Post. But the details remain fuzzy. The Ukrainian army is already skirmishing with Russian-backed rebels around the town of Slavyansk; casualties on both sides growing; results inconclusive.

Meanwhile, Tymoshenko has accused her old rival of secretly cosying up to Russia. In March, Poroshenko and Klitschko met with billionaire Dmitry Firtash in Austria. Firtash made his fortune from murky intermediary gas pipeline deals with Gazprom; he is fighting attempts by the US to extradite him on corruption charges. It is well known he has close Kremlin contacts.

Putin's view of Poroshenko – an implacable foe or a man he may be able to do business with – is unclear. Some believe that recent de-escalatory moves by Russia suggest the Kremlin may view him as an acceptable interlocutor.

In reality, though, there's little evidence Poroshenko is a Russian patsy. The businessman has paid a high price already for his outspoken pro-western views. Last summer Moscow banned chocolates from his Roshen factory in Lipetsk, southern Russian, supposedly on health grounds. In March riot police shut down the plant and seized its warehouse. Poroshenko also lost his shipyard in the Crimean port of Sevastopol when Russian troops overran the Black Sea peninsula. He has vowed to use all levers to get Crimea back.

The US and EU already appear to regard Poroshenko's victory as the most likely outcome. In late March Poroshenko visited London, together with Klitschko. They held talks with David Cameron and William Hague, the foreign secretary, and agreed a deal to make it easier for Ukrainians to get long-term British visas.

Outside Downing Street the pair chatted to pro-Ukrainian demonstrators. Poroshenko posed with the Ukrainian flag, a symbol that has practically vanished from much of the east.

With Ukraine's future as a sovereign state in doubt, and Russian troops on the border, Poroshenko will need all the international help he can get. Plus the bravery he demonstrated on the Maidan. Nobody has quite forgotten what happened to Yushchenko, who was mysteriously poisoned while on the campaign trail in 2004. "He is a very determined person. There is a physical risk to Petro," Temerko said. "He is a brave guy."

The chocolate king



Created in 1996, Poroshenko's company Roshen produces more than 300 kinds of sweets, cakes and biscuits at factories in Ukraine, Russia, Lithuania and Hungary.

Perhaps top of the list is the slightly unimaginatively named Cherries in chocolate, a cherry liqueur smothered in dark chocolate.

They are certainly sweet, but then people in this part of the world are famous for their sweet tooth. "They are tasty and always of decent quality," said Lyudmila Miroshnychenko, from Kherson, southern Ukraine. Cherries in chocolate, for her, is a treat to take with coffee in the afternoon.

Then there is Evening Kiev, a sort of Ferrero Rocher for the east, though frankly most ambassadors in Kiev haven't had much time of late for spoiling guests.

There is an entire range of chocolate bars that retail for around 20p – cheaper than imported Mars bars or Snickers. But many Ukrainians prefer the smaller chocolate sweets in colourful wrappers purchased by weight, some of which have retained brand names that were popular in Soviet times, like Camomile or Red poppy.

Svitlana Tuchynska, a Ukrainian who moved to Malaysia, said she always asks people travelling from Ukraine to bring her some Roshen candies. "I'm not a sweet tooth but once I presented some of Ukrainian Roshen sweets to Malaysians and Chinese locals they were delighted," she said. "And the Europeans also adore them. My friends from Sweden have always been purchasing Cherry in chocolate."

Roshen has not escaped the turmoil unsettling the region. Some residents in Donetsk and Luhansk have started a boycott of the sweets, just as they are boycotting the presidential election.

"Many people say they will not buy Roshen on principle," said Irina, who works in a supermarket candy department in Luhansk.

But if Poroshenko becomes president, he will take the politics out of chocolate for good: he has declared he will sell his company if he is elected on Sunday.