Vice President Dick Cheney (search) is "unpatriotic" because of his efforts to avoid military service during the Vietnam era, Teresa Heinz Kerry (search) said in a television interview aired Thursday night.

In an unusually vigorous foray into election-year politics, the outspoken prospective first lady slammed the vice president's activities during the Vietnam War (search) while defending her husband, Democratic presidential candidate John Kerry.

"To have a couple of people who escaped four, five, six times and deferred, deferred and deferred, calling [Kerry] anything or doubting his heroism is in and of itself unpatriotic," Heinz Kerry said. She added that she was referring to Cheney's lack of military service and to the attacks from the Bush campaign on various aspects of the Vietnam service of her husband.

For months a central feature of the presidential campaign has been the military backgrounds of Kerry, a decorated Vietnam War hero and Bush, whose National Guard (search) service has been scrutinized by critics. Cheney has also been criticized by Democrats, who note that the vice president once said he had "other priorities" than military service during the Vietnam War. While the Bush campaign has not explicitly charged Kerry as unpatriotic, Kerry has said that the criticism of his war record and his position on defense issues are attempts to raise questions about his patriotism.

His wife's remarks inspired an angry backlash from the Bush-Cheney campaign.

"Yesterday, Teresa Heinz Kerry called the vice president of the United States 'unpatriotic.' This political line of attack is offensive and should be stopped," said Bush-Cheney '04 Campaign Chairman Marc Racicot in a statement on Friday.

"Every time the discussion focuses on John Kerry's Senate record of voting against weapons systems, voting against support for troops in the field or his positions on both sides of critical questions of national security, his campaign falsely claims that his patriotism is being attacked. John Kerry's campaign is the only one that has ever raised questions about anyone's patriotism," Racicot continued.

The interview with Heinz Kerry, originally conducted by Telemundo and replayed on NBC Nightly News on Thursday, throws gasoline on the long-burning fire over the candidates' military histories.

Last week, Kerry said the president "couldn't even account for his whereabouts" during his Alabama National Guard service, and other Kerry surrogates have accused Bush of being absent without leave from his National Guard service in 1971

Republicans, including former Bush senior adviser Karen Hughes, have raised questions about Kerry's conflicting statements regarding whether or not he threw away his Vietnam medals or ribbons. Bush surrogates have also offered wide-ranging criticisms of Kerry's voting record on defense and military issues.

Spouses are generally off limits in presidential campaigns, but by attacking Cheney so directly Heinz Kerry has entered uncharted territory.

Normally vice presidential candidates spar with one another, but since Kerry has not named his choice for vice presidential nominee, the Kerry campaign has used other spokespeople to address issues connected with the vice president.

Fox News' Carl Cameron contributed to this report.