Attorney General Phil Weiser holds a lead over U.S. Sen. Michael Bennet among likely voters less than a week before ballots are due in Colorado’s Democratic gubernatorial primary, according to a new poll released Thursday by a group backing Weiser.

The survey, conducted Wednesday and Thursday by Democratic firm Public Policy Polling, found Weiser with 45% support to Bennet’s 36%, with 19% undecided.

Fighting for Colorado, a state super PAC formed to support Weiser, commissioned the poll, which has a margin of error of 4 percentage points. PPP interviewed 600 likely voters — including Democrats and unaffiliated voters who said they’ll cast ballots in the Democratic primary — using a mix of landline calls and text messages.

Primary ballots started going out to most Colorado voters on June 8 and are due back to county clerks by 7 p.m. on June 30.

Bennet and Weiser are slugging it out for the chance to run in November for the office held by two-term Democratic Gov. Jared Polis, who faces term limits. Three Republicans — state Sen. Barb Kirkmeyer, state Rep. Scott Bottoms and ministry leader Victor Marx — are vying for the GOP nomination.

The new poll shows a big jump in support for Weiser in the three weeks since the same firm conducted its first publicly released poll in the primary race, which found Bennet leading Weiser 36%-30%, with 34% undecided. That poll had a 4.4 percentage point margin of error.

According to the pollster’s memo summarizing the new poll, Bennet, who has been in office since 2009, has better name recognition among those surveyed, with 80% saying they know enough about him to have an opinion, compared with 65% who say the same about Weiser, who was first elected in 2018.

Voters who are familiar with Weiser prefer the two-term attorney general 62%-25%, the pollsters said, while Bennet trails Weiser 48%-41% among voters who are familiar enough with the three-term senator.

The pollster also found Weiser holds a 62%-21% lead over Bennet among voters younger than 45, with Bennet leading 43%-37% among older voters.

A spokesman for the super PAC that commissioned the poll said in a written statement that the results show Weiser with more room to grow than his better-known rival in Tuesday’s primary

“The dynamics of this race always suggested that Bennet was well-known to Colorado voters, having served 17 years in the U.S. Senate, while Weiser was lesser-known but well-liked by those who knew him,” said Curtis Hubbard, a public affairs consultant and spokesman for Fighting for Colorado.

“It takes 50 percent (plus) 1 to win, but in the closing days of the campaign, Weiser’s ceiling is higher than that of the incumbent senator,” Hubbard added.

A spokeswoman for Bennet’s campaign didn’t respond to a request for comment.