New Jersey's Senate candidates remained locked in a tie, according to a poll released Thursday that also showed confusion about the candidates among state voters.

Among 404 likely voters, 45 percent preferred Democratic Sen. Robert Menendez while 44 percent backed Republican challenger Tom Kean Jr., according to the Rutgers-Eagleton poll. The error margin was plus or minus 5 percent.

Among 660 registered voters, 42 percent backed Kean while 40 percent chose Menendez. This survey had an error margin of 4 percent. The survey of both likely and registered voters was conducted Sept. 24-26.

The poll showed there was ample opportunity for either candidate to take this race. Murray Edelman of the Eagleton Center for Public Interest Polling said about half of all registered voters said they have not heard of the candidates or do not have an opinion of them.

Only 36 percent of voters correctly identified Menendez as their senator. Menendez was appointed to the seat in January by Gov. Jon Corzine to serve out the remaining year of his term. He served 14 years as a congressman from northern New Jersey.

Eight percent of registered voters said Kean Jr. was the governor of New Jersey, an office held by his father, Thomas Kean. Another 8 percent thought that Kean, a state senator, was a U.S. senator.

"The candidates have a ways to go to capture the attention of the voters," Edelman said. "The major campaign advertising has yet to begin, and the ads could have a considerable effect considering the lack of voter knowledge about the candidates."

The survey also showed that 51 percent of voters associated Kean closely or somewhat closely to President Bush, while 50 percent said Menendez was very closely or somewhat closely associated to Corzine.

Bush's job approval rating was 30 percent, an all-time low for the president in this poll. Corzine's job approval rating was 48 percent, up three points since June.