TRENTON -- The state Assembly will vote Thursday whether to join the state Senate in supporting a lawsuit to stop new regulations from Gov. Chris Christie's administration that could make it easier to legally carry handguns in New Jersey.

The Democratic-controlled Senate voted Monday mostly along party lines, 21-16, to pass a resolution approving legal action against the rule adopted last week by the Republican governor's administration.

The Assembly, which is also controlled by Democrats, will take up the measure (SCR149/ACR234) at its Thursday voting session at the Statehouse in Trenton.

State Senate President Stephen Sweeney (D-Gloucester) said Christie is circumventing and "violating the will of" the state Legislature by instituting the rule.

After Christie unveiled the rule change last year, both houses of the Legislature -- the Senate and the Assembly -- passed a resolution to block it. Christie's administration moved forward last week despite the resolution.

"We're not going to let him ignore us," Sweeney said after Monday's vote. "He's not the king; he's the governor."

New Jersey is one of the toughest states in the nation to obtain a permit to carry a handgun. Residents must show they have a "justifiable need" to get one, proving there are "specific threats or previous attacks demonstrating a special danger to applicant's life that cannot be avoided by other means."

Critics say the definition is so narrow that only former law enforcements officers and current armored car guards qualify.

But last April, Christie's administration unveiled the revised regulation, which would allow a chief of police or the State Police superintendent to consider evidence of "serious threats" that are not directed specifically at an individual but establish "more than mere generalized fears or concerns" when considering a permit application.

Last week, Christopher Porrino, the state attorney general under Christie, announced that the state has formally adopted the change.

Democrats argue the new rule would allow cab drivers, delivery drivers, and anyone working in high-crime neighborhoods to carry guns.

Top Democratic lawmakers told NJ Advance Media last week that they now planned to sue to block the rule. This week's votes are the formal process to push forward with a lawsuit.

Christie said on a recent radio show that Democrats are "wrong" and "we'll fight them."

"We expect to prevail in any challenge," he said.

Democrats were successful with a similar approach when Christie's administration changed rules dictating how public workers in the state's civil service system are promoted. The Legislature passed a resolution to stop the new rules and the administration moved forward with them, but a court struck down the rules in December.

Brent Johnson may be reached at bjohnson@njadvancemedia.com. Follow him on Twitter @johnsb01. Find NJ.com Politics on Facebook.