MADISON, Wis. -- Gov. Jim Doyle's lead over U.S. Rep. Mark Green in the gubernatorial is continuing but has narrowed, according to a WISC-TV poll.

LISTEN: Doyle Campaign Responds (MP3 Format) | LISTEN: Green Campaign Responds (MP3 Format)

With slightly more than a month from the Nov. 7 election, the survey of 600 likely voters from around the state found that 48 percent said that they would vote for Doyle and 42 percent said that they would support Green.

Green Party candidate Nelson Eisman drew 1 percent.

Nine percent of those polled said that they are undecided. The margin for error for this poll is plus or minus 4 percentage points.

Doyle's lead is down from a previous poll last month that had the Democrat with a 9-point lead over his Republican rival, who is a congressman from the Green Bay area. Doyle had 49 percent while Green had 40 percent support. Eisman's support was at 1 percent. Another survey in mid-August had Doyle with 48 percent and Green with 38 percent.

University of Wisconsin-Madison political science professor Charles Franklin said that Doyle's 44 percent job-approval rating among independent voters could be an opening for Green. Among those independent voters, 47 percent said that they'll vote for Doyle compared with 40 percent for Green.

"If the race is about swing voters at all, then the independent ambivalence about Doyle's handling of his job could be Green's best chance to pull ahead," said Franklin.

Franklin said that on the other hand, if the race is about motivating the base voters, both campaigns are equally positioned because Republicans and Democrats are supporting their candidate by similar one-sided margins.

"If that is the game, then turnout is the key," said Franklin.

Regionally, Doyle has a big advantage in the Madison area. Fifty-nine percent support the incumbent governor while 28 percent back Green.

In Green's home turf of Green Bay, the race is much tighter. Forty-five percent support Doyle with 44 percent favoring Green.

Doyle's job-approval rating is hovering near 50 percent but fell slightly in the survey. In August, he registered at 48 percent overall. In September, it was at 50 percent. In this latest October poll, he dipped back below the magic mark to 48 percent.

The poll found that Doyle is favored among women, but Green has a lead with men in the state.

The recent survey was conducted by Research 2000 from Oct. 2 to Oct. 4 and paid by WISC-TV. Participants were polled by phone and were people who said that they vote regularly in state elections.

Stay tuned to WISC-TV and Channel 3000 for continuing coverage.