PHOENIX — Arizona's 2010 immigration enforcement law is being called a lingering hindrance to Phoenix's ability to lure gatherings to its convention center.

Convention center bookings are down by about 30 percent from 2009, while guest bookings in cities with comparable convention facilities are gradually increasing or stable, The Arizona Republic reported last week.

The immigration law known as SB1070 is one of several possible factors, with others including the recession and tighter strings on corporate and government travel.

However, other cities with comparable convention facilities have slowly rebounding or relatively flat guest counts, the Republic reported.

National conferences and meetings are scheduled years in advance, and Phoenix officials said they are just now feeling the full impact on visitation.

"The misperception that our city does not value diversity continues to be an impediment to attracting national convention groups," said Scott Dunn, a spokesman for the Greater Phoenix Convention and Visitors Bureau. "In some cases, the damage from what happened in 2009 or 2010 won't wash ashore until 2013 or 2014."

Though talk of boycotts has largely dissipated, Dunn said three large groups recently told the visitors bureau they were not considering Phoenix for their meetings because of the immigration issue.

City Councilman Jim Waring, a Republican former legislator who supported SB1070, said he thinks any adverse economic impact of the law is overplayed.

"That's a pretty hefty drop-off; to me, that speaks to other challenges," Waring said. "I would be surprised if 1070 played much of a factor."

Councilman Michael Johnson has met with organizations across the country and said many worry about how their members will be treated in Arizona.