Bartender, Iowa City will have another round of 21-only bar debate.

Two people associated with downtown Iowa City bars want a public vote on the city ordinance that bans people younger than 21 from being in drinking establishments at night.

Late Tuesday, George Wittgraf, owner of the Union Bar, and Josh Erceg, a manager at Martinis, filed with the city an affidavit stating their intent to seek a referendum to repeal the so-called 21-only law, City Clerk Marian Karr said Wednesday.

They need the signatures of 2,500 registered Iowa City voters on a petition to require the City Council to either adopt the proposal to repeal 21-only or to send it to a public vote.

Its an issue that has come up with regularity in this university town the past decade.

In spring 2010, the City Council passed an ordinance that bans people younger than 21 from being in places with liquor licenses after 10 p.m., with limited exceptions. After a petition forced an election, voters upheld the law, 52 percent to 48 percent, that November.

A public vote for a 21-only law failed in 2007. The City Council discussed, but never passed, an ordinance in 2004 and 2003.

Wittgraf said Wednesday that his primary reason for seeking a repeal is for students. He said the law has not had a great financial effect on his business because the 19- and 20-year-olds still come in but do so earlier and leave by 10 p.m.

I think theyre tired of leaving at 10, he said.

He said hes confident they can get enough signatures in the next month, with the focus being on students. Those students will need to be registered to vote in Iowa City, though.

Also, the University of Iowas spring term ends in two and half weeks.

The pressure is on. The next three weeks well know right away whether or not this will happen, Wittgraf said.

If a valid petition is filed by June 10, the issue could be on the ballot in the November election, Karr said.

Opponents have argued the law would hurt downtown businesses and push drinking to house parties.

Supporters say that those predictions have not come true and that crime and drinking statistics show the law has reduced problem drinking.

A university-city group called the Partnership for Alcohol Safety in March reported decreases in possession of alcohol under the legal age citations, disorderly house arrests and calls for disturbances downtown.

It also said a health assessment found a 19 percent decrease in the number of frequent high-risk drinkers and an 18 percent decline in students drinking 10 or more days a month between 2009 and 2012.

Mayor Matt Hayek doubts the City Council will be interested in reversing the ordinance.

Over the last three years downtown has become safer, more vibrant and better balanced, he wrote in an email. The university is stronger and the sky-is-falling predictions did not come to pass. I think the community recognizes 21-only is working.

Nic Pottebaum, 22, who just completed a term as president of UI Student Government, said students probably would sign the petition. But with the law three years old, he thinks the issue has fallen off most students radars and he doesnt hear a clamor for a return to 19-and-older bars.

There has definitely been a huge cultural change downtown, as far as the students go, he said, adding that he supports 21-only.