Los Angeles Mayor Antonio Villaraigosa on Monday will unveil a $5-billion, five-year plan to build housing for the poor and middle class.

The blueprint, which calls for thousands of new homes along subway and bus lines, and developments with people of all incomes living together, would, according to the mayor's deputies, alter the look and feel of the city forever.

But the plan, which many City Council members and business and housing groups said they had not yet seen, is being released while the housing market is a shambles, the state is facing a massive budget shortfall and the economy is teetering -- challenges that lead some to wonder whether it is feasible.

"I know that budgets are tight . . . credit is almost nonexistent," Villaraigosa said Saturday to a room full of community and labor groups pushing for more affordable housing. "But we're going to reject the cynics . . . and build a brighter future for those kids who are in the corner over there."

The mayor got a standing ovation at the union hall near downtown Los Angeles, and chants of "Si, se puede" ("Yes, we can") from the dozens of people in matching red T-shirts in his audience.

Some developers object to a so-called mixed-income provision that would require [subsidized] housing to be included in new housing developments. They say that such a policy -- which labor and housing groups have been pushing for years -- would cast a pall over entrepreneurial efforts.

"It is going to make housing less affordable for everybody," said downtown activist Brady Westwater.

On the other hand, community and labor groups, key players in the city's politics, are lobbying hard for the so-called mixed-income plan.

Los Angeles was designated the least affordable metropolitan area in the country last year, according to the Business Council report, because so many people pay so much of their incomes for housing.

The city also has the largest homeless population in the nation.

In addition, although private developers have built many high-end apartment units and condos over the last few years, there has not been a similar increase for households earning less than $75,000 per year.

Under the mayor's plan, the city would pledge $200 million a year for five years from various sources, including the city's Housing Authority, its affordable housing trust fund and its Community Redevelopment Agency, to build affordable housing.

In his address to thousands attending the National Council of La Raza conference, Villaraigosa criticized the Bush administration for what he called its "selective enforcement" of immigration laws.

He said that the federal government should focus its efforts on "criminals instead of working people," and that current enforcement practices unfairly tear families apart and punish small businesses.

Before introducing Villaraigosa to the thousands attending the conference Saturday, La Raza President Janet Murguia urged members to be respectful of both candidates, reminding them that La Raza is a nonpartisan organization.

He said 12 million illegal immigrants can be brought "out of the shadows and into the light, and onto the tax rolls by electing Barack Obama."

A letter sent to Mormon bishops and signed by church president Thomas S. Monson and his two top counselors calls on Mormons to donate "means and time" to the ballot measure.

In May, California's Supreme Court overturned a voter-approved ban on same-sex marriage, saying gays could not be denied marriage licenses.

"The church's teachings and position on this moral issue are unequivocal. Marriage between a man and a woman is ordained of God and the formation of families is central to the Creator's plan for His children," the four-paragraph letter states.

The latest letter is a disappointment to members of Affirmation, an international support group for gay, lesbian and transgender Mormons.

Last month, Affirmation called on the church not to meddle in California politics.

"This initiative will hurt so many people," executive director W. Olin Thomas said in a statement Monday.

"The California law affects civil marriage; it has no effect on any religious institution or official."

Affirmation leaders are scheduled to meet with the head of LDS Family Services, a church social services agency, in August to begin a conversation meant to bridge the divide between Mormonism and gay members hurt by church teachings that homosexuality is a sin.

"The California electorate is coming into a new age realizing that [neutered] marriage is an institution that supports family values, and it's certainly one I support," Villaraigosa said. "I certainly respect people of faith who disagree. I also respect the law, and I'm sworn to uphold the law."

Villaraigosa was deputized to perform marriages by the Los Angeles county clerk before the ceremony, and he is cleared to officiate weddings through Oct. 31.

For more than 2 1/2 years, Mayor Antonio Villaraigosa has been the public face of Los Angeles, appearing in one neighborhood after the next and often leading the nightly news.

But over the last two months, he has devoted noticeable time and energy to a cause outside the city. By today, the mayor will have spent 18 of the last 65 days on the road for presidential candidate Sen. Hillary Rodham Clinton (D-N.Y.) -- visiting Iowa, New Hampshire, Nevada and Texas as the primary election season has intensified.

Deputy Mayor Sean Clegg said Villaraigosa views the Clinton campaign as an investment in the city's future. A Democratic president, the mayor believes, would concentrate money and attention on the needs of big cities.

"The mayor said it many times: This is the most important presidential election in his lifetime," Clegg said.

Villaraigosa has become one of Clinton's most loyal and effective voices on the stump, a prominent Latino politician who has drawn crowds in Las Vegas, San Antonio and other heavily Latino areas. Since October, he has visited Nevada five times, Iowa three times, Texas twice and New Hampshire once, according to a schedule provided by his office.

His tireless efforts have not gone unnoticed by Clinton, who singled out Villaraigosa after she won Nevada's Democratic caucuses in January. The mayor has been talked about as a potential Cabinet nominee in a Clinton White House, although he has said privately that he has no interest in such a job.

On the stump, Villaraigosa travels with a press deputy from his City Hall staff and members of the Los Angeles Police Department security detail that accompanies him around the clock whether he is in the city or away.

The mayor's office said the Clinton campaign covers the cost of flights and hotels for him and his press aide, but the two pick up their food expenses. The city typically pays the travel, hotel and food costs for the LAPD officers, according to police spokeswoman Mary Grady. On three occasions in the fall, the Clinton campaign paid hotel and airfare expenses for the officers before those involved realized that the city covers the costs.

The two press aides who trade off campaign swings -- Matt Szabo and Janelle Erickson -- use their vacation time as well as personal cellphones on the trips because they are barred by city and state law from engaging in political work on the job.