Home Field Advantage-a group of local business and community leaders advocating for a new Vikings stadium-said last week that Minneapolis stands to lose more than $500 million if a stadium deal isn't reached.

The group's assertion is based primarily on an accounting of major events that have been held in Minneapolis but whose organizers have indicated that they wouldn't return to the city unless a new stadium is built. It claims that those events-ranging from the Super Bowl, which would have an economic impact of $250 million, to the Alcoholics Anonymous International Convention, valued at $70 million-would have a collective economic impact of $533 million if held in the city.

In addition to those events, Home Field Advantage claims that millions of dollars in revenue from other sources would be lost if the Vikings left town. For example, the city would lose an estimated $2.2 million in parking revenues; $12 million in state and local government taxes; and $34.8 million in hotel, retail, bar, and restaurant spending, the group said. Mankato, meanwhile, stands to lose the $5 million it sees each year from the Vikings' training camp, according to Home Field Advantage.

When tallied up, the money that the state stands to lose totals $587 million, the group said.

“If we can't get the stadium deal done and the Vikings organization leaves Minnesota, it would be a serious loss for our entire community,” U.S. Bank CEO and President Richard Davis, a partner of Home Field Advantage, said in a statement. “The loss of an NFL franchise would have a negative effect on our economy and our future ability to grow and attract jobs.”

The group's projections, however, are quite speculative, as it's unclear if and when the events cited by Home Field Advantage would actually be held in Minneapolis if a new stadium is built. And other recent efforts from the group to drum up support for a new stadium have been met with skepticism.

Home Field Advantage is a partnership that includes the Minneapolis Downtown Council, the Minneapolis Regional Chamber of Commerce, Meet Minneapolis, business leaders, city officials, and sports executives. The group recently released the results of a poll it commissioned, which indicated that 61 percent of Minnesotans support the current proposal to build a new Vikings stadium at the Metrodome site in Minneapolis.

According to a report by Minnesota Public Radio (MPR), the survey polled 1,000 Minnesota voters, and Home Field Advantage touted the following results: 61 percent of respondents support the current financing plan; 73 percent said they are following the stadium issue closely; and 72 percent say it's somewhat or very important that the Vikings remain in Minnesota.

But MPR reported that the results distributed by the group “don't entirely reflect the 'survey instrument' that seems to have originated the poll.” In other words, the survey asked additional questions-including who would be held responsible if the stadium deal fell through and the team left-but those answers weren't made public.

The Star Tribune, meanwhile, pointed out that the Home Field Advantage survey questions didn't go into detail about the main obstacles that the stadium plan faces, such as whether state general fund money might be needed as a backup funding source. The Minneapolis newspaper also said that the survey's results painted a different picture than those that it has conducted, which have found that the majority of Minnesotans oppose using public money for a stadium.

The Minneapolis stadium proposal was announced by Governor Mark Dayton, Minneapolis Mayor R.T. Rybak, and Vikings representatives early last month. It calls for Minneapolis to pitch in $150 million, while the Vikings and the state would pay $427 million and $398 million, respectively.

The plan suffered an immediate setback as a bill for the $975 million stadium stalled during its first legislative hearing before a Senate committee.

The main sticking point in the plan involves the state using electronic pull-tabs to pay for its $400 million contribution to the stadium's cost, but the proposal is showing some signs of life again. It recently gained support from the majority of the Minneapolis City Council, and the stadium bill on Monday cleared its first hurdle in the legislature by passing a House committee vote, according to media reports.

The Star Tribune reported that the House passed a measure that includes back-up funding sources for the state's share of stadium costs—but it immediately received criticism from opponents. And Dayton reportedly took aim at one provision to allow so-called “tip board betting” on professional sports games, which he said would violate federal laws.

The stadium proposal reportedly could get more hearings in both the House and Senate this week before the legislature begins a 10-day spring break. Read more about the stadium plan at the legislature in this Star Tribune story.