efe-epaStrasbourg, France

Spain's prime minister on Wednesday urged lawmakers in the European Parliament not to be dragged into nationalist political movements that he said threatened the integrity of the bloc.

In a speech at the EU's legislative branch, leader of the Spanish Socialist Party (PSOE) Pedro Sanchez declared himself passionately pro-European and warned against emergent right-wing populism on the continent.

"Such barbarism, that we thought we had banished from the history of this continent, re-emerges when nobody expects it," he told MEPs. "It is fed by forces that always put hate ahead of reason," he added.

Without mentioning specific groups, he said nationalists presented a threat to the integrity of the EU.

He also said the European Parliament elections scheduled for May would prove a challenge.

Many political analysts predict a surge in the far right when EU voters take to the polls.

"You should continue to defend European values and resist those who sound the siren of authoritarianism because they only have one objective: destroy Europe," Sanchez said.

Spain was witnessing its own re-emergence of the far right in the shape of Vox, a party founded by disgruntled members of the right-wing Popular Party, which entered the regional parliament in Andalusia following recent elections.