Tensions are escalating, especially in Los Angeles and San Francisco, as hospitality workers' union UNITE HERE—which has been involved in labor disputes with hotels in both cities since the fall—has begun calling meeting planners, asking them to boycott the 24 hotels at issue.Hoteliers as well as national and local meetings industry organizations are firing back, calling for an end to this tactic and a resolution of the dispute, though they also are making contingency plans.At least two large groups moved their meetings to other cities as a direct result of the union's boycott request. The most recent departure, announced in February for a conference that would have put almost $2 million into San Francisco's coffers, appears to be the last straw for some local tourism officials."Now that we're losing bigger and more significant groups, and this has gone on for more than six months, I'm hoping we might be able to have the mayor mediate a discussion during which the doors are kept locked until a settlement is reached," says Mark Theis, vice president of convention sales at the San Francisco Convention and Visitors Bureau. "No one should be allowed to leave until there's a handshake."The Organization of American Historians last month decided to move its 2005 meeting, which starts on March 31, from the Hilton San Francisco to San Jose. The hotel also lost the American Anthropological Association last fall when the group moved its meeting to Atlanta. The conventions, respectively, are estimated to be worth $1.8 million and $3.5 million to the city.Girding itself for the worst, the bureau has contacted 50 large groups scheduled for meetings in the next five months to provide updates on the contract negotiations. Hotel officials are trying to negotiate with groups that have canceled or those that are now on the fence as their meetings approach. In a show of support for the hotels, Meeting Professionals International, the Professional Convention Management Association, and the American Society of Association Executives released a joint statement that lashed out at UNITE HERE for its efforts to incite event cancellations. The statement says in part, "We do not condone UNITE HERE contacting meeting planners directly and asking them to boycott particular hotels either involved in ongoing labor negotiations or not at all involved but affiliated with certain major chains."