Updated 4:16 p.m. | Sen. Frank R. Lautenberg, D-N.J., will not seek re-election, setting up a lively Democratic primary for his seat in 2014.

CQ Roll Call confirmed Lautenberg’s decision, which he explained to The Newark Star-Ledger in a report published Thursday.

“I am not announcing the end of anything. I am announcing the beginning of a two-year mission to pass new gun safety laws, protect children from toxic chemicals and create more opportunities for working families in New Jersey,” Lautenberg told the paper. “While I may not be seeking re-election, there is plenty of work to do before the end of this term and I’m going to keep fighting as hard as ever for the people of New Jersey in the U.S. Senate.”

Garden State operatives expect more than one Democrat will seek the seat. Last year, Newark Mayor Cory Booker announced he had formed an exploratory committee to look at a bid. Rep. Frank Pallone Jr. is also eyeing the seat, along with possibly other state politicians.

Booker didn’t mention his Senate ambitions in a statement responding to Lautenberg’s retirement.

“On a personal note, Senator Lautenberg has been a strong model of leadership and service to me since before I even considered entering elected office,” Booker said. “I look forward to continuing to work with him for the remainder of his term in senate and for many years to come.”

Lautenberg, 89, had topped retirement watch lists for the cycle, thanks, in part, to his feeble $11,000 fundraising haul in the last quarter of 2012.

But state operatives questioned his intentions after Lautenberg repeatedly taunted Booker. Last month, the senator suggested the Newark mayor deserved a “spanking” for being “disrespectful.”

But in the end, Lautenberg opted against re-election, paving the way for a feisty Democratic primary between Booker and, possibly, Pallone.

A Monmouth University/Asbury Park Press poll released Thursday morning showed Booker with a commanding lead; other candidates only registered in the single digits.

But sources in New Jersey say Pallone has quietly courted the state’s influential machine. That goes a long way in a state where county parties determine ballot placement. Plus, Pallone reported $3.4 million in his campaign account at the end of the year.

The Newark Star-Ledger recently floated Assembly Speaker Sheila Oliver’s name as well.

Additionally, Geraldo Rivera, a well-known television personality, has indicated he might run for the seat as a Republican. However, New Jersey GOP operatives are not taking the notion seriously.

Most likely, this open seat race will likely have zero impact on the makeup of the Senate in 2015. CQ Roll Call rates this race as Safe Democratic.

Lautenberg holds the rare honor of having occupied both of his state’s Senate seats in his lifetime. He served in the Senate from 1982 until his first retirement in 2000.

In 2002, Lautenberg ran again for Senate after Democrat Robert G. Torricelli withdrew from his re-election race in the final weeks because of ethical issues. Lautenberg is credited with saving the seat for desperate Democrats.