Considered a faithful "number two" man, Oleksandr Turchynov now has a stab at the top spot in Ukraine -- for the time being.

A politician and evangelical preacher who has authored psychological thrillers, Turchynov was named interim president on Sunday by the opposition-controlled parliament in a bid to fill a political void left by the impeachment of Viktor Yanukovych and to end a three-month-long crisis.

The right-hand man of ex-premier Yulia Tymoshenko, who walked free on Saturday after being jailed by the ousted regime, the 49-year-old is seen as a compromise figure with little political ambition and a deep loyalty for the fiery opposition leader.

"He's always the number two man, even in his own party," said Balazs Jarabik, senior fellow at the Central European Policy Institute.

He was Tymoshenko's deputy prime minister between 2007 and 2010 and is currently deputy chairman of her Batkivshchyna (Fatherland) party, having looked after affairs while she served a seven-year jail sentence that was cut short on Saturday.

Now he is interim leader of a country on the verge of default and ravaged by political crisis since November, when protesters rose up against Yanukovych over his decision to ditch an EU pact in favour of closer ties with Russia. He faces the unenviable task of overseeing a return to stability until elections on May 25.

- 'Faithful sword-bearer' -

Analysts say Turchynov has few political ambitions, and may have been named interim president so that opposition figures with a desire to run for office can avoid staining their names before polls take place.

"He has worked with different politicians, but he has never aspired to be a leader, it's his psychological characteristic," said Volodymyr Fesenko, a Kiev-based political analyst.

"He won't take part in the presidential elections. It's very probable that Tymoshenko will aim for the presidency and Turchynov will organise her electoral campaign. He has a lot of experience in this regard."

Turchynov, who ran for mayor of Kiev in 2008 but lost, may also have been elected interim president to keep Tymoshenko in the loop and allow her to continue to weigh in on parliamentary decisions from afar.

"Turchynov's future is Tymoshenko's party, where he will never pretend to play the main role. He will remain her faithful sword-bearer," said Fesenko.

- Expert on shadow politics -

A keen writer, he has authored several psychological thrillers for which his brief seven-month stint as head of Ukraine's SBU intelligence services in 2005 may have provided some fodder.

He put together the screenplay for "Illusion of Fear", a 2008 film based on his book that Ukraine submitted to the Oscars as its foreign-language film entry.

The plot tells the story of a successful entrepreneur who is forced to defend a business project against gangsters, and starts losing contact with reality.

The book has numerous references to the Bible and to God, Turchynov being a member of the Evangelical Baptist Church.

He has also authored academic papers devoted to researching shadow economy and politics. One of his essays focused on the links between clans and political power.

But even those who worked in Tymoshenko's government say he is a closed-book character.

"He's not very talkative, he's not very open," said one such person who refused to be identified.

"People know very little about him, apart from the fact that he is very close to Tymoshenko and she can trust him."

Born in the industrial city of Dnipropetrovsk, just like Tymoshenko, he worked briefly in a steel factory. He launched his political career at the beginning of the 1990s.

In 1993, he became economic advisor to President Leonid Kuchma and later created his own party, which Tymoshenko integrated.

Both were elected lawmakers in 1998, and they later created the Batkivshchyna party.