Iranian President Hassan Rouhani said on Saturday that the government aims to hold "free" parliamentary elections next year, the official IRNA news agency reported.
"The success of the government to is to hold free, healthy and competitive elections," Rouhani said in a speech to governors and provincial governors.
Iranians will vote for a new parliament on February 26, 2016, when elections for the Assembly of Experts in charge of appointing, supervising and dismissing the supreme leader are also due.
Rouhani said politicians should be allowed to speak freely in public, regardless of their views.
"Preventing someone from making a speech by sticking a label on him" is unacceptable.
His comments come weeks after dozens of protesters threw bricks at the taxi of outspoken MP Ali Motahari in the southern city of Shiraz as he planned to deliver a speech.
Motahari has frequently criticized the regime's house arrest of opposition leaders Mir Hossein Mousavi and Mehdi Karroubi.
The pair were placed under house arrest in 2011 after repeatedly challenging the official 2009 election results.
Since the attack on Motahari, several reformist figures have been also prevented from giving speeches across Iran.
Rouhani also insisted state institutions must remain neutral in the election.
The president, elected in June 2013 with the support of reformists and moderates, also requested that transparent ballot boxes be used at next year's vote to avoid fraud.
Ballot boxes in Iran are usually opaque plastic or wrapped in a white fabric.
"We must abandon these practices to avoid accusations against the regime," of vote-rigging, he said.
