DENVER — Bob Beauprez is right on Tom Tancredo’s heels atop the four-candidate GOP gubernatorial field, according to a new survey by Magellan Strategies released Tuesday.

The survey of more than 900 likely Republican primary election voters, conducted May 28th and 29th, shows Tom Tancredo atop the field with 27 percent support.

Beauprez, who didn’t enter the race until late February and has been spending a lot of his own money to try to consolidate the anti-Tancredo vote behind his campaign, is polling at 25 percent, within the poll’s three percent margin of error.

Secretary of State Scott Gessler, who launched his own ad campaign Tuesday attacking Beauprez and Tancredo as failed former gubernatorial candidates of years past, draws 13 percent support in the poll.

Former Senate Minority Leader Mike Kopp has 10 percent support.

That leaves 25 percent of those polled undecided as ballots are mailed out this week in advance of the June 24 primary election.

The Magellan survey was commissioned by Beauprez’s campaign, which has been on the airwaves for the last month.

“Today as Republicans start to receive their ballots, Bob is well positioned to win the primary, which gives Republicans their best opportunity to defeat [Democratic Gov. John] Hickenlooper and return strong leadership to Colorado,” Dustin Olson, Beauprez’s campaign manager, wrote in an memo to staffers Tuesday.

Tancredo, looking to close the deal, is out with his own TV ad, portraying himself as a motorcycle-riding, anti-establishment “tough guy” who also has a softer side.

Tancredo’s support is probably the deepest of the four candidates in the field, but it may not be broad enough to win more than 35 percent of the vote in this four-way contest.

That dynamic leaves Beauprez trying to peel off voters from Gessler, who’s raised a decent amount of money of late, and Kopp, who’s currently bicycling across the state.