Describing Sprem as a friend, Prime Minister Zoran Milanovic said politics was a job that made a man bad and wondered if this job had poisoned Sprem. He recalled that Sprem got sick with a "treacherous, unstable, desperate illness."
Milanovic described Sprem as optimistic, honest and kind, as well as successful despite being modest. He said the late speaker was sometimes boyishly naive, yet determined, firm, with clear goals, which made him successful.
"Everyone who was close to him can be proud of that success because Boris achieved it in an honest manner. He played by the rules, which is the hardest thing to do in life," Milanovic said, concluding with, "Bye, dear friend. Bye, Boris."
Acting Parliament Speaker Josip Leko said Sprem had brought to Croatian politics a new spirit of closeness, immediacy and humanity.
He said that despite a relatively short time as parliament's speaker, Sprem had managed to set new standards in running the parliament in a wish to restore citizens' trust in it and state institutions ahead of Croatia's accession to the European Union.
Leko said Sprem had performed each of his many duties responsibly and professionally, and that his appointment as parliament speaker had returned him to the walk of life in which he could give the most - democracy and the fight for the commonweal.
For Sprem, social democracy was not just one of the possible political options in Croatian politics but the only possible option which ensures prosperity and social equity, said Leko.
Illness and death prevented Sprem from having in parliamentary debates more democracy, responsibility, quality and tolerance, he added.
"I am confident that strengthening parliamentarianism in Croatia is the common aspiration of all of us here and that, following the common interest, we will succeed in this term in office to achieve that political goal," Leko said, adding that this would be the greatest expression of gratitude to Sprem and his vision of a democratic parliament.
President Ivo Josipovic said that with his kindness and wisdom, Sprem had ennobled many lives in Croatian politics by immeasurably loving Croatia and its people.
"Our citizens and our homeland have lost a politician who always saw to the commonweal and worked to the benefit of our citizens."
Josipovic said Sprem had performed his duty as parliament speaker with remarkable honour and success, and that all his colleagues, regardless of political affiliation, loved him because of his honesty, conciliatoriness and readiness for dialogue.
"He consistently abided by what he announced as he stepped into the office of parliament speaker - that we must show through deeds that we serve citizens, that we are not led by personal, group, corporate or partisan goals," said the president.