TRENTON — The idea of making tenure tougher for New Jersey teachers to get and easier to lose took a big leap forward Monday when a state Senate committee advanced a bill and Gov. Christie endorsed it.

Bills on the issue have won committee approval in both chambers of the state's Legislature in the last five days, with the support of the state's education-advocacy cottage industry.

The Senate bill was put together by Teresa Ruiz (D., Essex), who worked out the details with groups representing a variety of interests. A stream of those advocates, including officials of two teacher unions and a socially conservative group, urged passage of the bill in testimony before the budget committee, which approved it unanimously.

"After watching these disparate groups come up here in unanimity, I have a new assignment for you," Sen. Loretta Weinberg (D., Bergen) told Ruiz. "We're going to send you to the Middle East to take on the peace process."

Making it easier to fire low-performing teachers is a big issue for many advocates for education reform — and a cause that Christie has championed. But there are difficult issues. Among them: How do schools determine which teachers are ineffective? How can teachers be protected from being fired just because they disagree with their administrators?

Ruiz's bill would use an evaluation method, now being tested by the state, that employs state test results to determine part of a teacher's grade. And instead of having tenure charges handled through the courts, in a process that can last more than a year, they would be directed to arbitrators, who would be required to wrap up cases within three months.

While the education groups support her bill, several have complaints about pieces of it.

The New Jersey Principals and Supervisors Association says it's a problem that only a limited number of grievances could be appealed. The New Jersey School Boards Association says arbitrators would lean toward the unions. The New Jersey Education Association wants it also to apply to educators at charter schools.

And some advocates, including Ruiz, would have preferred a bill that would have eliminated a key protection for teachers: the use of seniority, not performance, to determine who is let go in layoffs.

Christie often talks about wanting to change that. But he signaled Monday that he could accept the compromise. "We have been supportive of Sen. Ruiz's efforts on tenure reform and will await the final bill," his spokesman, Michael Drewniak, said in a statement.

While the issue has gained momentum in the Legislature after years of debate behind the scenes, it's not settled. There are differences in many of the details between Ruiz's bill and the one advanced last week by an Assembly committee. For instance, the Senate bill would require tenure charges to be filed against teachers who have poor ratings two years in a row. In the Assembly bill, they would not be required until three consecutive "ineffective" ratings.

Other measures that advanced in Trenton on Monday: • The Senate Health, Human Services and Senior Citizens Committee voted, 7-3, to approve legislation that relaxes a proposed ban on the use of indoor tanning salons by teenagers under 18 that the Assembly approved last month. The Senate measure would ban indoor tanning by anyone under 16, while 16- and 17-year-olds could tan as long as a parent was present for purchase of the sessions. It would prohibit child customers from tanning on consecutive days. • The Assembly Appropriations Committee approved on a 9-0 vote a measure mandating that nonviolent drug-dependent offenders who would benefit from treatment be sentenced to the state's drug court program rather than prison. The measure, which heads to the full Assembly, phases in the statewide program over a five-year period, beginning with at least three counties in the first year. Participation in drug court is currently voluntary. • A measure making it easier to convict drivers of vehicular homicide or assault by auto when they kill or injure someone while using a cellphone moved a step closer to becoming law. The bill, approved unanimously by the Assembly Appropriations Committee, provides that the illegal use of a cellphone while driving can be considered driving recklessly, one factor in finding a person guilty of vehicular homicide or assault.