TRENTON - The president of the state Senate said Thursday that he would not allow a vote on a bill that would weaken the governor's power to appoint a replacement for a U.S. senator who leaves office early.

Richard J. Codey, a Democrat, said the legislation would send the wrong signal if it were passed just before Republican Gov.-elect Christopher J. Christie is sworn in.

"It's the wrong time to do it," Codey said. "I would hope at some future time, we would pass a bill that would allow for this when it doesn't give the appearance it's aimed at" Christie.

Codey's decision effectively kills efforts to strip Christie of the authority to replace either of New Jersey's two Democratic U.S. senators with a Republican if a vacancy arises. Codey controls the Senate's agenda until the current legislative session ends Jan. 12. Christie takes office a week later.

The governor can fill vacancies without regard to party. He also has the power to call a special election or leave the seat vacant until the next general election.

Two proposals to change how Senate vacancies are filled in New Jersey were introduced this month as Christie, the state's first Republican governor in eight years, waits to be sworn in. The state's senators - including the Senate's second-oldest member, 85-year-old Frank Lautenberg - are Democrats. Democrats hold majorities in both houses of the state Legislature.

Codey said he agreed in principle with proposals introduced by fellow Democrats in the Assembly, John McKeon, who represents the same Essex County district as Codey, and Joe Cryan, the incoming Assembly majority leader, of Union County.

"I think both John and Joe are right in that the replacement should be of the same party, just like it is in local government," Codey said.

New Jersey has not elected a Republican to the U.S. Senate in more than 30 years.

Christie reacted angrily when Democrats raised the issue after he unseated Gov. Corzine on Nov. 3.

"This is a political power play by the party that is losing power," Christie said then. "Gov. Corzine did not complain, nor did members of the Legislature complain, when Gov. Corzine used the exact system that is in place today to appoint his replacement."

Corzine chose Bob Menendez, then a member of the House of Representatives, to succeed him in the Senate after Corzine won the 2005 New Jersey gubernatorial election.

McKeon's bill would restrict Senate replacements to the same political party as the elected senator. Cryan's bill would require that the seat be left vacant until voters could select a replacement.

"He's wrong," Cryan said of Codey. "The senator says this is political, and it is. It's in the interest of mainstream New Jerseyans who haven't elected a Republican to the U.S. Senate since 1972."

Governors in 37 states can fill Senate vacancies; in Arizona, Utah, Wyoming and Hawaii, the replacement must be from the same political party as the vacating senator, according to the National Conference of State Legislators.

In September, Massachusetts lawmakers fulfilled Sen. Edward M. Kennedy's dying wish by granting the governor the power to appoint an interim replacement for him so President Obama could regain a critical 60th Senate vote to pass a health-care overhaul.