Connecticut GOP Senate nominee Linda McMahon is hammering Democratic Attorney General Richard Blumenthal for misstatements about his military service record amid polls that show the race between them tightening.

In a blistering new ad that the McMahon campaign says will air statewide, the Republican rebukes Blumenthal for claiming he served “in” Vietnam. Blumenthal apologized in late May for making misstatements.

{mosads}“Would you lie about serving in a war?” the ad’s narrator asks. “Dick Blumenthal did again and again … He lied about Vietnam. What else is he lying about?”

In the ad, Blumenthal is shown saying, “We have learned something very important since the days that I served in Vietnam.”

Most polls show Blumenthal and McMahon running in a close race, with Blumenthal leading only by single digits despite the state’s liberal tilt. Before the controversy over his service record began, Blumenthal led McMahon by over 20 points in polls.

McMahon’s campaign dropped the ad hours before a debate with Blumenthal Monday night. A McMahon aide told The New York Times that the timing of the ad was meant to throw Blumenthal off.

“It’s another desperate attack from a losing campaign with nothing to say,” Blumenthal’s campaign manager, Mindy Meyers, said in a statement. “Linda McMahon’s money can’t buy Dick Blumenthal’s genuine record of standing up and fighting for the people of Connecticut.”

If the GOP wins the race to replace retiring Democratic Sen. Chris Dodd, it would greatly improve the party’s chances of winning a Senate majority, as Blumenthal has boasted a lead for most of the race.

The firestorm surrounding Blumenthal’s service record began after the Times reported in May that Blumenthal repeatedly misrepresented his military service in the Vietnam War. On several occasions, Blumenthal said he served “in” Vietnam and recounted vivid tales of returning from combat.

McMahon’s campaign appears poised to use the line of attack throughout the final month of the race. Hours after the Times published its Blumenthal story in May, her campaign posted material on its web site taking credit for leaking it to the newspaper, but it later backed away from the claim

Blumenthal did serve in the Marine Reserves during Vietnam, but he carried out his duties domestically.

McMahon, meanwhile, has come under attack from Democrats for her tenure as CEO of World Wrestling Entertainment. They accuse her of failing to crack down on the use of performance-enhancing drugs. Several wrestlers who in recent years died at young ages were discovered to have used the substances.

Blumenthal’s campaign issued a memo leading up to the debate, hitting McMahon for her treatment of wrestlers during her time as executive and for her relationships with lobbyists.

“Linda McMahon will have a lot to say tonight about her record at WWE, her personal history and her policies if elected — but so far, she has refused to clarify several troubling questions about her record and her views,” the memo said.

In their own memo Monday morning, Senate Republican strategists expressed cautious optimism about the race.

“Linda McMahon has taken perpetual liar Dick Blumenthal’s lead from 41 points this January to a mere four points today,” National Republican Senatorial Committee Executive Director Ron Jesmer wrote Monday in a memo. “These polls were recently validated by the [Democratic Senatorial Campaign Committee’s] decision to purchase media last week in an attempt to defend Blumenthal.

“Clearly, national Democrats weren’t planning on spending money in a state so handily won by President Obama in 2008.”

This story was originally posted at 11:59 a.m. and updated at 7:35 p.m.