The finale of the Eurovision Song Contest this weekend is expected to draw a staggering 200 million viewers from around the world. But like every year, deciding who should be crowned the winner may not come down to a question of singing ability or stage presence; it may come down to politics.

The 60-year-old singing contest in which viewers phone in to vote for their favourite has always largely been political, says Karen Fricker, a professor of Dramatic Arts at Brock University who is in Vienna for Saturday's grand finale.

"The thing about the contest that is so crucial is it's a song contest of nations," she told CTV's Canada AM Friday.

"What goes into the reasons that people vote is always going to be about more than the songs; it always has been. So you can use the contest as a barometer of what's going on in Europe more broadly," she said.

After several elimination rounds, the contest is now down to 27 nations competing for the win, with performers from Sweden, Italy, Russia, Estonia and – oddly – Australia considered the favourites.

Last year, bearded Austrian diva Conchita Wurst walked away the winner, earning headlines around the world, even in places where few had ever heard of Eurovision before.

Since then, Wurst has become a huge celebrity in Europe, playing sold-out gigs, penning a bestselling biography, meeting with United Nations Secretary-General Ban Ki-moon, and addressing the European Parliament on LGBT rights.

"She's used her win as a platform to campaign for tolerance around Europe and beyond," says Fricker.

"And she's been extremely effective – much more than other recent winners – in using Eurovision as a way to get a message out."

With the contest in Vienna this year (the winner's nation usually hosts the next year's competition), Wurst is quite literally all over Vienna. Not only is she a co-host of the show, she's also the voice on the u-Bahn, Vienna's subway system, announcing station stops, Fricker says.

"So they've really exploited her presence because she's become such a beloved figure," she said.

The annual competition purports to be removed from politics, but politics have a way of infusing themselves in. Last year, when tension in the Russia-Ukraine crisis was running high, Russia's entry, the Tolmachevy Twins, were booed on stage.

This year, Ukraine chose not to send a candidate. But the Russian contestant, Polina Gagarina, is still managing to raise eyebrows with a song about fraternity called "A Million Voices."

"The song is extremely effective and I would argue, manipulative," says Fricker, "because it's one of those songs that's all about how we should all get together and link hands and be human beings together and believe in peace.

"We have to bear in mind this song is representing Russia, a country that is very involved in aggressive foreign relations at the moment."

Gagarina hasn't managed to earn any boos from the crowd. While that may be a reflection of the Ukraine situation falling off the top of the news agency, Fricker says "it's also perhaps because fans just love the song."

With files from The Associated Press