Former World Wrestling Entertainment CEO Linda McMahon and Rep. Christopher Murphy (D) could see a tough general election fight to replace retiring Sen. Joseph Lieberman (I), according to a Quinnipiac University poll released this morning.

In a test of a November matchup between the two, Murphy took 46 percent to McMahon’s 43 percent, a result within the poll’s 2.6-point margin of error.

The poll confirmed both Murphy and McMahon are heavily favored to win their respective primaries, with McMahon receiving the best news from the poll.

“Linda McMahon is now the clear frontrunner for the GOP nod,” Quinnipiac University Poll Director Douglas Schwartz said in a press release. “McMahon also is doing better against Congressman Chris Murphy, the front runner for the Democratic nomination. She is essentially tied with Murphy after trailing by 15 points in March.”

Murphy led former Connecticut Secretary of State Susan Bysiewicz 50 percent t0 20 percent in a test of the Democratic primary. McMahon led former Rep. Chris Shays 50 percent to 30 percent among Republicans surveyed.

Schwartz noted a reason for McMahon’s growth: she has spent heavily on television advertising. Over the last six weeks, she has been the only candidate on the air.

McMahon’s favorability ratings among all respondents have increased as well. Her favorable/unfavorable rating was underwater in March, but now 45 percent of those who know her have a positive opinion of her, while 38 percent view her unfavorably.

The Murphy campaign jumped on the news with an email to supporters with the subject line: “McMahon’s money is working.”

“It’s simple — her money advantage is working,” Murphy campaign manager Kenny Curran wrote. “McMahon’s already spent $3 million on TV ads to rehabilitate her image, and we don’t have the money to be on the air right now.”

Curran ended the email with a solicitation for donations.

The poll was conducted May 29 to June 3. Quinnipiac interviewed 1,408 registered voters in live interviews via land lines and cellphones. The margin of error among that group was 2.6 points. The poll included 381 Republicans, with a 5-point margin of error, and 538 Democrats, with a 4.2-point margin of error.

Roll Call rates this Senate race as Likely Republican.

Correction: 3:19 p.m.

An earlier version of this post incorrectly identified the campaign that emailed supporters and for which Kenny Curran works. Both were the campaign of Christopher Murphy.