Iraq has threatened to fine journalists covering local elections on January 31 if they report inaccuracies or back any candidate.
Media organisations which flout the Communications and Media Commission's mandatory code of conduct could also have their equipment confiscated or be forced to make a public apology.
Media organisations could have their licences revoked if they fail to pay any fines.
Iraq is one of the most dangerous countries in the world for journalists, who are routinely targeted by extremists.
"We reject this interference," said Muaid al-Lami, head of the Iraqi Journalists' Syndicate, who survived an assassination attempt when a bomb detonated outside his office in September.
"We agreed journalists should not defame others ... but this doesn't mean we should allow interference in their work," he said, adding the union was capable of ensuring its members meet ethical standards.
A senior official at press freedom watchdog Reporters Without Borders said the code was unnecessary and open to abuse by Iraq's government because the terms were so vague.
Tension is rising as Iraq's provincial elections approach.
Shi'ite parties are vying for dominance of the oil-rich south as Arabs and Kurds compete to control the north.