As many as 50.3 percent of those polled claimed they were not in favor of secession, the newspaper said.
On September 27, Catalonia will hold regional elections. Several coalitions of pro-independence parties have pledged regional autonomy from Spain should they win the vote.
Over 80 percent of Catalans who participated in a November 2014 vote supported secession from Spain. More than two million people out of an estimated 5.4 million eligible voters took part in the informal, non-binding ballot.
Spanish Prime Minister Mariano Rajoy has repeatedly refuted Catalonia’s right to secede.