New London — The two candidates for U.S. Senate engaged in their most substantive policy debate yet Monday night, discussing tax cut ideas, foreign policy stances and how they would pass legislation if elected to Washington.

But the hour-long debate between Democrat Chris Murphy and Republican Linda McMahon was punctuated and often interrupted by the loud audience inside the Garde Arts Center.

The audience, officially estimated in size at 625, disobeyed rules against applause and booing. Although both candidates' closing statements were interrupted and even drowned out by audience noise, Murphy was interrupted more.

"Linda McMahon brought a bunch of people here to try to shout me down off the stage because she's afraid of debating," Murphy said afterward. "She didn't fare too well in the first two debates, so her tactic tonight was to try and bring a bunch of people who would disrupt the debates."

McMahon's campaign hotly denied the charge. Speaking with reporters after the debate but before Murphy's allegation, McMahon said the interruptions made it hard for her to answer questions.

"They seem to be very supportive on both sides," McMahon said. "It was a very lively crowd."

Venue organizers said the repeated disruptions resulted in McMahon's closing statement being cut from live television because the program ran over its time allotment.

McMahon's campaign manager, Corry Bliss, later issued a news release that called on WTNH-TV to play McMahon's two-minute closing statement in its entirely during their late newscasts.

"It is unfortunate Linda's statement was disrupted, but we believe the voters of Connecticut deserve to hear both sides in this important election," Bliss wrote.

Audience naughtiness aside, the evening featured informative statements and policy positions from the rival candidates, especially for viewers who missed the first two debates. The winner on Nov. 6 will replace Sen. Joe Lieberman, who is retiring.

Murphy, the current 5th Congressional District representative, attempted to paint McMahon as selfish plutocrat who would contribute to "obstructionism" in Washington and exacerbate income inequality and the nation's deficit problems with more tax cuts for high-income people like herself.

"The idea that you only create growth by investing in the wealthy just runs against everything that has made this nation and this state great," he said.

For her part, McMahon described the three-term congressman and former state legislator as another politician "whose chief aspiration is a political career."

As she did throughout earlier debates, McMahon repeatedly mentioned her six-point plan for jobs creation and its tax cuts for the middle class and businesses.

Under McMahon's plan, the top corporate tax rate would drop to 25 percent from 35 percent and certain loopholes would be eliminated. The income inequality gap would begin to close under her plan, McMahon said, "because we will have the middle-class back to work."

When asked how she, if elected as Connecticut's freshman senator, would get such a far-reaching plan passed in Washington, McMahon replied that her plan offers something for both parties, and she would build coalitions to get it through.

McMahon later returned to one of her favorite attack lines: Murphy has no jobs plan despite nearly six years in Washington.

Murphy again disputed the claims. "I don't have to talk about my plan as much as Linda McMahon does because I have a record."

"But I will admit that I'm pretty sure I'm not going to get it word-for-word passed," Murphy added, "so that's why you have to elect somebody who knows how to reach across the aisle."

Murphy said he would extend all Bush-era tax cuts except those on individuals earning more than $200,000 and couples earning more than $250,000. Half the money from ending those tax cuts should go to paying debt, Murphy said, with the rest toward investments that benefit regular citizens and the middle class.

"I am proud of my plan," Murphy said. "It invests in middle-class tax cuts, it invests in manufacturing, it invests in our schools and it invests in renewable energy."

McMahon has also called for extending the Bush-era tax cuts, including those for high earners. She said she would be open to tax increases on the wealthy in the future, provided that the economy improves and the revenue from the taxes goes to debt repayment.

The candidates differed in attitude toward the U.S. Supreme Court's controversial Citizens United decision that allowed for unlimited political spending by corporations and labor unions.

McMahon said she supports the decision because she considers it a First Amendment issue guaranteeing free speech.

But Murphy said that big corporate spending "corrupts our democracy" and said McMahon's position on the issue — one generally taken by Republicans — is out of step with Connecticut.

Both candidates said they oppose Iran fielding nuclear weapons.

Murphy said it is premature to speculate on whether he or any other candidate would support a preemptive attack on Iran, but called for drawing "a line in the sand" in dealing with the country.

McMahon said the sanctions against Iran appear to be working, and she is for continuing and perhaps strengthening them. She called for a full defense of Israel.

"I believe an attack on Israel is an attack on the United States," she said.

At other points in the debate, Murphy and McMahon both called for greater discussion about the nation's debt.

"The greatest threat to our national security is our debt," McMahon said.

Monday's debate was sponsored by The Day, the Garde, WTNH-TV and the Robinson & Cole law firm. Paul Choiniere, editorial page editor of The Day, and Mark Davis, chief political correspondent for WTNH-TV and Channel 8, took turns asking the questions. The next and last debate is scheduled for Thursday afternoon in Hartford.

The race's outcome will help determine control of the U.S. Senate. Democrats currently hold a slim 51-person majority over the 47 Republicans and two independent senators. There are 23 Democratic seats and 10 Republican seats up for election this year.

j.reindl@theday.com