Los Angeles City Councilman Richard Alarcon pledged again Tuesday to require Providence Holy Cross Medical Center in Mission Hills to do an environmental report before undergoing a major expansion.

In a news conference at City Hall, Alarcon said he supports the expansion but believes the report is needed to protect the surrounding community in the northeastern San Fernando Valley from traffic and other effects. Alarcon accused hospital officials of "avoiding their environmental responsibilities" by not conducting a full review of the 120,000-square-foot project.

And he accused hospital officials of distorting his position, saying that its television and newspaper advertisements imply that he opposes the expansion.

"I'm ashamed that a faith-based organization would use this ploy, use highfalutin' media consultants to send this wrongful message, this inaccurate and false message that we do not support the expansion," Alarcon said.

Hospital officials said that doing the report would delay the 136-bed expansion by 18 months and cost them millions of dollars. They also said the environmental impact report was being sought by unions that seek to organize the Providence Health and Services, a nonprofit that operates 28 hospitals in the western United States, about half of which have employee unions.

"It's all about the union," said Kelly Kurcz, the director of emergency services and trauma care at the hospital. "Our organization is pro-employee, and our employees don't want a union."

Joining Alarcon at the news conference were several members of the community and of Community Advocates for Responsible Expansion at Providence Holy Cross. The two spokesmen for the group work for the Los Angeles Alliance for a New Economy, a pro-labor organization whose chairwoman is Maria Elena Durazo, the secretary-treasurer of the Los Angeles County Federation of Labor.

The group's Bay Area attorneys also frequently work for the Service Employees International Union.

Danny Feingold, one of the group's spokesmen, said the dispute was not about unions.

"This is a broad-based and diverse coalition," he said, adding that the groups want only to ensure that the project benefits the community.

Also present at City Hall on Tuesday were lobbyists and consultants who work for the hospital. Among them were Tim McOsker, the former chief of staff to then-Mayor James K. Hahn, and longtime political consultant Rick Taylor.

At least three other neighborhood councils in the area support a full environmental study. But the Mission Hills Neighborhood Council, which represents the area around the hospital, supports the expansion without the full study.

"We decided that we'd rather have a partnership with the hospital instead of forcing them to spend a lot of money" on a full report "when they were addressing all the issues anyway," said David Crawford, chairman of the neighborhood council board.

The city Planning Commission voted 6 to 0 in July to allow the hospital project to proceed without the full environmental study.

Two appeals of the decision are scheduled for hearing by the City Council's planning committee on Oct. 23.