The leader of Spain's anti-austerity party Podemos said Sunday's "no" vote in Greece had strengthened the negotiating position of the government in Athens, which he was convinced would reach a deal with its creditors in coming days.
The closest European ally of Greece's governing SYRIZA party, Podemos emerged as one of the winners in Spain's recent local elections and has maintained the support of a significant minority of voters as the Greek crisis has rumbled on.
According to an opinion poll on Sunday, recently-founded Podemos is virtually tied with the country's two mainstream parties, with no sign of a front-runner emerging.
"The 'no' in the referendum boosts Greece's negotiating position to reach a sensible agreement," its leader Pablo Iglesias told a news conference. "…I'm very optimistic, I'm sure that in the next days we'll have an agreement."
Asked if the referendum was good for his party, Iglesias said: "It's not that the 'no' vote is good for Podemos, it's good for the people of Europe… We don't have to be worried by democracy."
Calling the event a political landmark for Europe, he said he was to discuss the result later on Monday with Greek Prime Minister Alexis Tsipras.
Podemos earlier condemned "interferences, manipulations and lies" from European institutions to label the "no" vote an anti-European vote.
"The message of the Greek people is clear: those in the European institutions, you are not above any of our people, are not above democracy and the European project does not belong to you," it said in a statement.