Iglesias didn't hold back in his address to the parliament, launching a blistering attack on the bloc, saying that officials in Brussels had contributed to the divide between the rich and poor.
"Fifteen months ago I said that we hoped for a different Europe, one that would be a little less tough on the weak and a little less complacent with the powerful," he said, in reference to his first address to the chamber in May last year.
"Unfortunately, I think that this statement is still valid today."
Iglesias criticized many MEPs over their stance towards the refugee crisis, slamming those "who cry crocodile tears and claim to defend human rights."
"We are talking once again about war and desolation at the doors of Europe, about families who are getting closed doors and barbed wire as an answer, and I say that we Europeans cannot forget what war means, what horror and poverty mean, and what it is to have to flee horror and poverty."
However, perhaps the harshest attack was saved for European Commission chief Jean-Claude Juncker.
Iglesias slammed Mr Juncker in a personal attack, accusing him of "encouraging tax fraud" by overseeing questionable tax deals given to multinational businesses during his 18 years as prime minister of Luxembourg.
"We cannot humiliate those people, because that is humiliating Europe and ending the welfare state, ending social rights and giving up our governments to the arrogance of financial powers. It means humiliating Europe and encouraging tax fraud, like you did, Mr Juncker, when you were treasury minister and fostered secret deals with multinationals so they would only have to pay one-percent tax."
To conclude, the Podemos leader, who is hoping to draw significant support away from traditional parties in the upcoming Spanish elections, pointed the blame at those responsible for electing Mr Juncker, such as Italian Socialist Group leader, Gianni Pittella.
"People like you, Mr Pitella, have allowed Mr Juncker to be sitting there, because you Socialists have maintained a great coalition with the People's Party in this chamber.
"I am returning to my country, so in Spain there will no longer be people like you in government."