TRENTON - Gov. Christie should nominate an attorney general to be confirmed by the Senate, New Jersey Senate President Stephen Sweeney said Monday, arguing that process was key to preserving the independence of the office.

Sweeney's remarks came as the attorney general's and governor's offices have come under scrutiny for settling a pollution case with ExxonMobil Corp. for $225 million after prosecutors had sought an $8.9 billion judgment at trial last year.

A former commissioner of the Department of Environmental Protection contended last week that Christie's chief counsel, Christopher Porrino, had "elbowed aside" the acting attorney general and pushed for the settlement. The governor's office denied the allegation.

"I think the administration should give us somebody, we should vet them and then approve them," Sweeney said in an interview.

Sweeney (D., Gloucester) didn't criticize acting Attorney General John J. Hoffman or say the ExxonMobil controversy necessitated a nomination.

But he noted that Hoffman has served in an acting capacity since June 2013, when Christie appointed the previous attorney general, Jeffrey S. Chiesa, to the U.S. Senate.

Christie later tapped his then-chief of staff, Kevin O'Dowd, for the post. But that selection was put on hold after the George Washington Bridge lane-closure scandal erupted in January 2014.

O'Dowd was not accused of wrongdoing, and Democrats, who control the Legislature, had said they would confirm him. O'Dowd left the administration last year to work for Cooper University Hospital.

"It's not like we were blocking it," Sweeney said. Christie "can say we block things, and he would be telling you the God's honest truth - we do. But we would like to have an attorney general that we could vote on. And then there's the independence, because that's the way the constitution wrote it - it removed the cloud or an appearance that people are talking about."

Asked if he knew whether the Republican governor, who visited Iowa last weekend in preparation for a presidential run, planned to file a nomination, Sweeney quipped, "Where's he at today? Is he here?"

Christie's office did not respond to a request for comment.

The state constitution says the "attorney general shall be nominated and appointed by the governor with the advice and consent of the Senate to serve during the term of office of the governor."

By contrast, the governor's appointment of a lieutenant governor does not require Senate confirmation.

Once confirmed by the Senate, the attorney general "does have a significant degree of independence from the governor," said Robert Williams, a Rutgers-Camden law professor who specializes in state constitutional law. "None of that is true for an acting attorney general."

While the New Jersey governor has the power to remove state officials, "to this day it's unclear whether that would apply to attorneys general," Williams said.

Williams didn't think Christie could be forced to nominate an attorney general. "It's kind of a loophole in the constitution," he said.

Former Republican Gov. Thomas H. Kean Sr. said governors were "very, very careful" about attorney general nominations. "Something goes wrong, you're stuck there," Kean said.

In 2006, Attorney General Zulima Farber resigned after a special prosecutor found she had committed ethical breaches by getting involved in her boyfriend's traffic stop.

Although it's better to have a confirmed attorney general in place, Kean said, governors also don't want a nominee "involved in a nasty confirmation battle."

New Jersey is one of five states in which the attorney general is appointed by the governor, according to the National Association of Attorneys General. Attorneys general in most other states are popularly elected, and some New Jersey legislators have called for the state to switch to that system following the ExxonMobil settlement. Sweeney is opposed.

"Every place I've seen it, they seem like they prosecute their political enemies and run for governor as soon as they get done," he said, adding that he opposed the idea of law enforcement officials raising money for elections, because that could raise conflicts of interest.

Democrats and environmentalists have slammed the ExxonMobil settlement, which stemmed from a lawsuit filed in 2004 alleging that the company's refineries and plants in North Jersey had polluted 1,500 acres of wetlands, marshes, and creeks for decades.

All that was left to determine at trial last year was what ExxonMobil owed in damages.

Hoffman announced the settlement last week, calling it the "single largest environmental settlement with a corporate defendant in New Jersey history."

It will be subject to a 30-day public comment period and must be approved by a Superior Court judge.

Sweeney and other Democrats have vowed to sue to block the settlement. On Monday, the Senate Environment and Energy Committee passed a resolution condemning the settlement and urging its rejection. That goes next to the full Senate for a vote.

Sweeney said the resolution would bolster the Legislature's court case.

aseidman@phillynews.com

856-779-3846 @AndrewSeidman