Iraq's parliament on Saturday voted to ban the sale, import and production of alcohol, in a surprise move likely to anger some minorities but also to please influential religious parties.

Proponents of the ban argue that it is justified by the constitution, which prohibits any law contradicting Islam.

But some opponents argue that it also violates the same constitution which guarantees the traditions of religious minorities.

According to an MP and a parliament official, the ban was a last-minute addition to a draft law on municipalities that caught the anti-ban camp flat-footed.

The law was also passed by MPs in Baghdad as all eyes were on the north of the country, where forces involved in Iraq's biggest military operation in years are battling the Islamic State group and moving to retake the city of Mosul.

"A law was passed today and article 14 of that law bans the import, production and sale of all kinds of alcohol," Yonadam Kanna, a veteran Christian MP, told AFP on Saturday.

"Every violation of this law incurs a fine of 10 million to 25 million dinars (roughly $8,000 to $20,000)," he said.

Kanna vowed to appeal the law in a federal court.

Alcohol is rarely offered in restaurants and hotels in Iraq, but consumption is relatively widespread, especially in Baghdad where scores of small shops selling alcoholic beverages can be found.

Iraq also has companies producing various types of alcohol, such as Farida beer or Asriya arak (a regional anise-flavoured spirit).

Kanna was furious after the vote, issued a statement and went on television to argue against the new law.

- More drugs -
"This article of the law goes against the constitution, which guarantees the freedoms of minorities," he said.

Article 2 of the constitution says it "guarantees the Islamic identity of the majority of the Iraqi people and guarantees the full religious rights of all individuals to freedom of religious belief and practice" such as Christians, Yazidis and Sabeans.

Ammar Toma, an MP who voted in support of the ban, argued that it was the constitution that made it illegal to sell, produce or import alcoholic drinks.

"The constitution says you cannot approve a law that goes against Islam," he told AFP, referring to an article stating that "no law that contradicts the established provisions of Islam may be established."

Kanna and Toma also differed on the impact of a ban.

"This law will put people out of jobs, drug consumption will rise, the economy will be affected," said Kanna.

Observers say drug abuse has been on the rise in Iraq recently, especially in the southern city of Basra, where trafficking with neighbouring Iran is soaring and where alcohol is only found on the black market.

Toma, a Shiite MP from the Fadhila party, rejected Kanna's assessment and said "the effects of alcohol on society are great, and include depravation, terrorism and social problems."

"As the for the people who will lose their jobs, new jobs can be found for them," he said without elaborating.