Mayor Ralph Becker is defending against a second round of attacks on the legality of Salt Lake City's domestic-partnership registry.

And he's sticking up for its title, too.

Sen. Greg Bell, R-Fruit Heights, plans to introduce a bill that would set guidelines by which local governments can recognize unmarried couples as financial co-dependents without undermining Amendment 3, the state's constitutional amendment prohibiting same-sex marriage and other domestic unions.

Though text of Bell's bill was not yet available Tuesday, its expected intent is to force Salt Lake City to modify its domestic-partnership registry.

Proposed by Becker and approved Feb. 5 by the Salt Lake City Council, the registry provides a mechanism by which employers voluntarily can extend health care and other benefits to their employees' domestic partners — including same-sex relationships, siblings, long-term roommates and parents — if they reside in Salt Lake City.

Becker and members of the Salt Lake City Council have called the ordinance a natural progression from the February 2006 action that extended health benefits to adult designees of city employees.

"The primary substantive effect of the (domestic-partnership registry) is to make it easier for the private sector, for businesses and nonprofits, to look to a standard if they want to extend benefits to domestic partners," the mayor said.

Bell said he doesn't want to block those benefits. But it's important that those benefits aren't exclusive to same-sex couples so they don't violate Amendment 3 or lead to broader policies that could ultimately overturn the state constitutional ban on same-sex marriage and other domestic partnerships.

"We want to preserve the rights of a city or county to provide for employer-related domestic benefits to be shared on a neutral criteria," Bell said.

Becker contends that Salt Lake City's domestic-partnership registry already meets that neutral criteria because it's open to all people in relationships of mutual support, caring and commitment.

"It isn't defined in terms of same-sex or opposite-sex," he said. "It's defined in terms of the relationship between two people."

Though he said Salt Lake City's registry isn't necessarily in direct violation with Utah's gay marriage ban, Bell takes issue the term "domestic partnership." He said the term can be interpreted as "gay marriage light" because the registry is limited to couples who are co-habitating.

Becker said the city's own adult-designee ordinance belies that description because 78 percent of city employees who have utilized the provision are not same-sex couples.

As for the term "domestic partnerships," Becker said it is a common term for an established relationship of mutual dependence.

"It's the standard term in many states and many, many cities," he said. "I don't know why we would want to depart from what has become a common term for recognizing this kind of relationship."

Bell's bill essentially replaces SB267, which sought to prohibit counties or municipalities from establishing a registry to recognize a domestic partnership other than marriage. Doomed by its troubled sponsor, Sen. Chris Buttars, R-West Jordan, the bill was sent to the Senate Rules Committee last week where it likely will remain the rest of the session.

The Senate voted Monday to allow Bell to open a late bill file on the same issue.

House Majority Leader David Clark, R-Santa Clara, said he hadn't see Bell's bill, but he said the House's reception of the bill would be independent of the shadow cast by Buttars' situation.

"The challenge is, does the underlying principle remain the same?" Clark said. "Irregardless of Sen. Buttars and Sen. Bell, is there an underlying appetite to change the policy?"

Bell said he's been working with Salt Lake City officials on the modified bill and that it will be different from Buttars' bill.

"We're trying to sculpt something that's acceptable to the stakeholders," he said.

Becker said he received a message Monday night from Bell in which the senator promised to share the bill's language with him when it's drafted.

"I've known Sen. Bell for a long time, and I have a great deal of respect for him," said Becker, a former legislator. "I'm certainly interested in talking to him about what his proposal is."