The election has become a three-way race between Zelensky, Poroshenko and Tymoshenko although at one point there were a record 44 candidates in the running — there are now 39.
The candidate polling in fourth place is pro-Russian candidate Yuri Boyko but he is very unlikely to make it through the first round of voting, analysts say.
Zelensky is leading the polls but he is a newcomer to politics — his nearest experience of presidency playing the president in a hit TV show. A win for incumbent Poroshenko would maintain a certain stability but there have been mutual accusations of corruption between him and Tymoshenko that they have both denied.
Viktor Andrusiv, executive director of the Ukrainian Institute for the Future based in Kiev, told CNBC that Russia will be observing the elections closely but would take a “wait and see” approach to the country’s next leader.
“They don’t have a candidate that they would prefer to win, apart from Boyko,” he said. “They know Poroshenko and they’re comfortable with him. In a way, they are accustomed to each other,” Adrusiv noted before adding that Russia was more interested in forthcoming parliamentary elections where it might have influence over a bloc of seats and can push their interests in Ukraine’s Parliament through pro-Russian candidates.
“For them, the name of the president is not something they’re interested in,” Andrusiv continued. “Whoever it is, they will have to deal with the situation in Donbass, the economic conditions in Ukraine. The Russians understand that any next president will have to deal with them.”