Brussels: An election win for Greece`s far-left Syriza party could cause political contagion across Europe by boosting support for other populists, as well as reopen the vexed question of EU-backed austerity, analysts said.
But other radical upstart parties such as Spain`s Podemos may find it a double-edged sword, especially if Syriza ends up backing down on its vows to reverse painful reforms imposed under Greece`s international bailout.
Syriza leads in the polls ahead of snap elections in Greece on January 25, called on Monday after the parliament failed to choose a new president, causing alarm in European capitals.
Analysts have played down the risk of financial contagion from a new Greek tragedy, but the main concern in Europe now is that it could benefit other radical parties that trade on growing disillusionment with mainstream politicians and Brussels.
If Syriza wins, "this may open a Pandora`s box by questioning the proceedings of many current governments, including the Italian government," Catherine Fieschi of the Counterpoint think-tank in London told AFP.
But Holger Schmieding of Berenberg Bank said that if Syriza failed to deliver on its "unaffordable promises", then "populists would be deflated (and) mainstream parties across Europe would find it easier to argue against the superficial allure of financially irresponsible populists".Eurosceptic parties did well in European Parliament elections last May and this year there are general elections in Spain, Britain, Estonia, Finland and Poland.
Podemos leader Pablo Iglesias exchanged celebratory tweets with Syriza leader Alexis Tsipras after the early election was announced.
The two men predicted that "2015 will be the year of change in Spain and in Europe".
Podemos has risen from nowhere since it was born from the Indignants protest movement less than a year ago. It now leads the polls in the runup to Spain`s elections in November.
At the other end of the spectrum, right-leaning, anti-immigration eurosceptic parties have hailed a possible Syriza victory as a boost, casting it as a triumph of the masses against the political elite.
UKIP leader Nigel Farage -- whose party is in the same group as anti-EU Italian comedian Beppe Grillo`s Five Star populist movement in the European Parliament -- said the snap Greek election was a good thing.
"Stripped of their own currency and plunged into poverty by Brussels control, the Greek people now have a chance to take back democratic control," he said.
French far-right leader Marine Le Pen hailed it in similar terms, calling it a "democratic dream" and a "victory for the people against the European oligarchy".But Syriza`s performance in office is the big question, especially after Tsipras suggested the party could take a less radical stance.
"If Syriza win in Greece, then populists everywhere will see opportunity to push an alternative vision of how to run countries and claim that voters can change things radically if they want," Simon Usherwood of the University of Surrey told AFP.
"However, winning an election isn`t the same as implementing policies -- so what`s dangerous for UKIP and others is that Syriza end up conforming to the current Greek position on austerity and troika requirements with only cosmetic changes, which wouldn`t surprise me," he added.
Mats Persson, director of the Open Europe think-tank, said a Syriza win would be a "testing ground for so many different things".
"The more interesting lesson that might be drawn is from what happens next, that will also be a lesson for Podemos. If Syriza will be able to negotiate Greece`s debts somehow, it will set a very complicated precedent for what Podemos would do."
Eurosceptic groups like UKIP, meanwhile, would "definitely make a big deal" of a Syriza victory as it suited their narrative of "the people rising up against Brussels and the elite," said Persson.
"There is a unifying theme across the left-right spectrum that is quite worrying."