(CNN) - With less than five weeks before Election Day, a new poll suggests that New Jersey's gubernatorial race is tightening up.
Governor Jon Corzine trails Republican challenger Chris Christie by four points, according to a Quinnipiac University survey of New Jersey residents likely to vote in the November 3 election.
Forty-three percent of people questioned in the poll, released Tuesday morning, back Christie - the former federal prosecutor in New Jersey - with 39 percent supporting Corzine - the Democratic incumbent who's fighting for a second term as governor - and 12 percent supporting Independent candidate Christopher Daggett.
Six percent are undecided.
The four point lead for Christie is within the survey's sampling error, and his lead is down from a ten point margin in Quinnipiac's most recent poll conducted a month ago.
The survey indicates that Corzine leads overwhelmingly among Democrats and Christie overwhelmingly among Republicans, with Independent voters breaking 46 percent for Christie, 30 percent for Corzine and 16 percent for Daggett.
The poll suggests that Corzine's approval rating remains low, with 36 percent of people questioned approving of the job he's doing as governor.
"Christopher Christie is still ahead in the Garden State, but when he looks in the rear-view mirror, he sees the bearded visage of Gov. Jon Corzine getting closer," says Maurice Carroll, director of the Quinnipiac University Polling Institute.
"This race looks as if it will go down to the wire. Does Christopher Daggett's impressive climb measure a swing to him or simply a distaste for the two guys hollering at each other? Will Daggett fade on Election Day? At this stage, his numbers matter," adds Carroll.
Christie is trying to become the first Republican to win a statewide contest since Governor Christine Todd Whitman won re-election in 1997.
New Jersey and Virginia are the only two states holding gubernatorial contests this year, and the Democrats are defending both seats. While both contests focus on state issues and the candidates themselves, both contests are also seen as an early referendum on President Barack Obama and the Democrats who control Congress.
The Quinnipiac University poll was conducted September 23-28, with 1,188 New Jersey likely voters questioned by phone. The survey's sampling error is plus or minus 2.8 percentage points.