Arizona Sen. John McCain, determined to keep pace with his better-financed Republican rivals, is launching his first television ad today in New Hampshire, a commercial describing him as the presidential candidate with "more courage."

The move follows a decision by McCain, who has about $2 million in the bank, a fraction of the sums available to Texas Gov. George W. Bush and Steve Forbes, to speed up his advertising timetable by two weeks. Aides say he is trying to capitalize on his recent gains in New Hampshire polls and avoid being drowned out by Bush's commercials, which began Monday, and Forbes's next wave of spots.

McCain's 60-second ad, opening with vivid footage from his 5 1/2-year captivity in North Vietnam, portrays him as a fighter who stands up to special interests.

Greg Stevens, the senator's media adviser, said the commercial shows how McCain's saga "connects with the qualities people are looking for in a president. People know he's a former POW; they know he's a maverick; they know he has taken on the establishment. What the advertising does is put it all together."

McCain, who has been promoting his best-selling autobiography, in recent weeks has appeared on "Meet the Press," "This Week," "Good Morning America," "Hardball," "Equal Time" and a host of other shows. Ed Gillespie, a GOP strategist, said McCain is adept at drawing media attention but also needs to join the air wars. "He can't match Bush or Forbes point for point, but you have to get up with whatever you can because it does help to define you," Gillespie said, adding that such ads in turn attract free media coverage.

In New Hampshire yesterday, McCain criticized Bush's school voucher plan, saying he opposes diverting existing federal education money from public to private schools. His more aggressive posture underscored his emergence as Bush's strongest rival for the nomination.

Bush has made school vouchers a centerpiece of his education plan. Last month, he proposed a program to give failing schools serving disadvantaged students three years to improve test scores. If those schools fail to do so, Bush said he would take some of the federal funds that go to disadvantaged students and convert them to vouchers that parents could use at schools of their choice.

"I would disagree with that view," McCain told reporters. "I would think that we should find another source of funding for a test voucher program, because you've only got a certain pot of money and you're taking it away from projects that are already funded and obviously there's somebody who's going to be hurt." McCain said he would rather finance school vouchers by eliminating federal subsidies for the oil and gas, ethanol and sugar industries. He said that would provide $5.4 billion for a three-year experimental program.

McCain also said he is reconsidering whether to compete in January's Iowa caucuses, rather than making the New Hampshire and South Carolina primaries the first tests of his candidacy. Citing Elizabeth Dole's withdrawal last week, he said: "Events change. We have to reevaluate again." But McCain criticized the caucus process, saying he believed he would do better in secret-ballot primaries than in caucuses, where voters' preferences are made in public meetings.

Balz reported from Manchester, N.H.

CAPTION: Sen. John McCain is trying to capitalize on recent gains in New Hampshire, campaign aides say.