TRENTON - Proponents of a controversial bill expected to win approval by the state Senate on Thursday say it will simplify New Jersey's complex and unpopular rules on how towns provide affordable housing.

Yet opposition has been mounting since the first version of the bill was introduced by Sen. Raymond Lesniak (D., Union) in January, and on Wednesday more than 100 organizations called for lawmakers to abandon the plan.

Critics say the proposal directs low-cost housing away from areas near employment hubs that most need it, while inviting sprawl to rural areas.

The measure would abolish the Council on Affordable Housing, which enforces municipal affordable-housing quotas. It was created by the legislature 25 years ago in response to Supreme Court rulings that towns had a constitutional obligation to provide low- and moderate-income housing. Developers, government officials, and housing advocates have been fighting over how best to achieve that ever since.

Lesniak and other supporters say the measure offers a simpler way for towns to provide affordable housing and returns authority to the local level.

The bill, known as S-1, requires that developers of residential housing set aside between 5 and 10 percent for affordable units. They could opt out of the requirement in several ways, however, including paying $10,000 per each unit that would have been affordable. That money would go toward rehabbing properties.

Yet the proposal could also ease the way for builders in some towns more than others.

The proposal deems about half of New Jersey's 566 municipalities "inclusionary," meaning they provide a variety of housing choices. Towns achieve the designation if 71/2 percent of their total housing stock is price-restricted, or at least one-third is single-family attached housing or mobile homes.

Projects by developers in towns that don't meet that standard would be considered "inherently beneficial" if they apply to the local zoning board for a variance, say, to construct homes at a higher density or in an area zoned nonresidential. Critics note that such a designation, already given for uses such as schools and hospitals, would favor the builder.

The bill "is going to lead to strange results, like wealthy municipalities getting off the hook and older towns that already have their fair share of affordable housing being expected to do more," said Kevin Walsh, of the Fair Share Housing Center, an affordable-housing advocacy organization in Cherry Hill.

The center provided a list of which towns would qualify as inclusionary, or "exempt," under the current bill.

Voorhees and Collingswood are considered exempt, but the list doesn't quite show that wealthy towns are universally getting off the hook - Cherry Hill, Mount Laurel, and Moorestown are all deemed not exempt.

Lumped into the same category are diverse communities that already have provided a lot of affordable housing, such as Pennsauken and Gloucester City.

Disproportionately affected are towns in more rural counties, such as Salem, Gloucester, and Cumberland in South Jersey, Hunterdon in the central part of the state, and Warren and Sussex in the northwest. Only a fraction of towns in those counties are exempt.

"All these places with more trees than people aren't exempt," despite the fact that they are not near jobs, noted Jeff Tittel, director of the New Jersey Sierra Club.

Yet it's also unclear how the proposal, if adopted, would mesh with current regulations restricting development in some remote areas such as the Pinelands.

Walsh noted that Senate President Stephen Sweeney (D., Gloucester) has not been vocal publicly about the measure, although it would disproportionately affect his county: Just seven of 24 towns in Gloucester County, including his hometown of West Deptford, are exempt.

"This is legislation that is affecting his district, and he's been asleep on it," said Walsh. "Now he's posted it for a vote."

Walsh and other advocates have wanted the Senate to postpone voting. They say that Lesniak has shut them and the public out of the legislative process.

"The Senate president agrees with the bipartisan consensus that mandating affordable housing through the arbitrary assignment of numbers not only won't work, but hasn't worked. . . . He supports S-1 and will vote for it," Derek Roseman, a spokesman for the Senate Majority Office, wrote in an e-mailed statement.

A spokesman for Gov. Christie declined to comment Wednesday and said the governor would speak on the issue Thursday. Christie recently unveiled a similar proposal to kill the Council on Affordable Housing.

The Fair Share Housing Center's list shows some interesting results in the Atlantic City area, which has a strong need for affordable housing for casino employees. Just outside the city, Brigantine, Ventnor, and Margate are considered inclusionary, though those towns have many expensive beachfront condos.

Among the areas in which the bill would instead target growth are farther-flung towns of Atlantic County such as Folsom, Buena Vista, and Port Republic.

Every town in Hudson County, across the river from New York City, is considered inclusionary. That includes Hoboken, home to former Gov. Jon S. Corzine's multimillion-dollar condo.

The bill is somewhat open-ended on how the state would guard against expensive condos and apartments counting toward the inclusionary designation, only saying that the state "may exclude buildings determined to be luxury dwellings."

The latest version of S-1 won approval by the Senate Economic Growth Committee on June 3. But housing advocates expressed frustration that the committee neither allowed public comment nor made available a copy of the amended bill before voting.

Christie has said he wants affordable-housing reforms to pass by June 30, also the deadline to pass the state budget.

Housing advocate Matthew Reilly said he did not understand "what appears to be a mad rush to get these reforms pushed through the way they're currently conceived," given that the subject is so complicated. Reilly, executive director of the affordable-housing nonprofit MEND in Moorestown, added that several towns his organization had worked with for years were unwilling to move forward on projects due to uncertainty over how the state's affordable-housing rules could change.

An April opinion by the nonpartisan Office of Legislative Services determined that an earlier, yet similar version of the bill could be susceptible to a legal challenge on constitutional grounds. It found that the proposal failed to assure that regional housing needs required by a Supreme Court ruling would be met through the set-asides.

Contact staff writer Maya Rao at 856-779-3220 or mrao@phillynews.com.