Ed Gillespie, Republican candidate for Virginia governor, left, and Ralph Northam, the Democratic nominee. (Bill O'Leary/The Washington Post)

Democrat Ralph Northam has a 10-point lead in the Virginia governor's race, according to a new poll of likely voters released on Tuesday.

Quinnipiac University found 51 percent of likely voters supported or were leaning toward Northam, compared to 41 percent for Republican Ed Gillespie. Libertarian Cliff Hyra drew 3 percent.

The findings conflict with several other polls this week that found Northam tied or with a slight edge in the Nov. 7 contest.

Another poll released Tuesday by Mason-Dixon Polling and Strategy found Northam essentially tied with Gillespie, with voters split 44 percentage points to 43.

Both results come a day after Suffolk University released a poll that found the race in dead heat and the University of Mary Washington released its poll that gave Northam a slight edge but still within the margin of error.

Quinnipiac also differed from other polls in finding Northam had a 13-point lead among independents, a somewhat amorphous group in a state where voters don't register by party affiliation. Virginia independents favored Donald Trump by five points in November and the 2013 GOP gubernatorial nominee by eight points.

The Quinnipiac poll identified gaps by race and gender. Northam, the sitting lieutenant governor, had a 58-point lead among non-white voters and 27-point lead among women voters, according to the survey. Gillespie had a slight edge among white voters, 49-44, and a 10-point lead among men.

Quinnipiac also found Northam had stronger favorability ratings than Gillespie, with 47 percent viewing him positively and 31 percent unfavorably. Voters were split about Gillespie, with 40 percent viewing him favorably and 39 percent unfavorably. Gillespie is a longtime Republican operative and former chairman of the Republican National Committee who ran unsuccessfully for the U.S. Senate in 2014.

The Mason-Dixon poll gave Northam a slight lead over women, and found nearly one in five black voters were undecided.

Virginia general election guide

Virginia's gubernatorial contest is the nation's marquee election this year, as the only competitive statewide race in November and an early test of swing-state politics in the era of President Trump.

Just 39 percent of Virginia voters approved of Trump's performance, according to the Quinnipiac poll, while 58 percent disapproved. It mirrored similar findings by polls including from the University of Mary Washington, which released results Wednesday showing Trump underwater with Virginia voters by a 55-37 percentage point margin.

Northam and Gillespie are participating in their first televised debate Tuesday evening, which will be aired 7 p.m. in Washington markets on NBC4/WRC-TV.

Quinnipiac pollsters surveyed 850 Virginia likely voters on landlines and cell phones between Sept. 14 and Sept. 15 and results have a margin of error of plus or minus 4.2 percentage points. Its latest survey is not comparable to early results, which polled registered voters.

Mason Dixon surveyed 625 registered voters using similar techniques between Sept. 10 and Sept. 15, with a margin of error of plus or minus 4 percentage points.

A variation of findings is expected as polls use different methods for drawing samples and identifying likely voters, a challenging task in Virginia's gubernatorial elections given that just over 4 in 10 voters cast ballots in the past two contests.

Scott Clement contributed to this report.