A spirited and somewhat bizarre battle is under way over the control and future direction of the National Organization for Women, the nation's most politically potent feminist group.

NOW leaders are very close-mouthed about the conflict, which pits the established leadership against Sonia Johnson, a controversial feminist considered "too radical" by many NOW stalwarts.

Johnson, who has never held a major post in the organization, wants to succeed Eleanor Smeal as president of NOW. Smeal is ineligible to run for another term, but the battle has become a referendum on her leadership and the direction she charted for the organization.

During her five years as president, Smeal built NOW into a major political force with 220,000 members and an annual budget of $13 million. She did so, in part, by appealing to the everyday concerns of average women in an attempt to shed the "bra-burning" image that plagued the movement in earlier years.

Many feminist leaders fear that Johnson's outspoken rhetoric and support of confrontation tactics might destroy the new image. Others resent the amount of money Johnson is spending in the race (she estimates $12,000) and the fact that she hasn't climbed the traditional NOW leadership ladder.

The challenge comes when NOW is at a crossroads. In the past, NOW has been synonymous with the drive to ratify the Equal Rights Amendment. With the defeat of the ERA, it has to decide whether to continue focusing most of its resources on another ratification drive or shift its agenda.

Smeal refuses to discuss the presidential race, which will be decided at NOW's 15th annual convention this weekend in Indianapolis.

So do Johnson's two leading opponents, Judy Goldsmith and Jane Wells-Schooley. Both are vice presidents of the organization, elected with Smeal and committed to remaining on the current course.

Johnson, the best known of five candidates, has waged an ambitious and expensive campaign. She has sent out direct mail fund-raising appeals, published a slick 16-page campaign booklet, and spoken before NOW members in 13 states.

A mother of four who used to live in Sterling, Va., Johnson describes herself as "a kind of a plain-looking, middle-aged woman" whom divorcees and other women identify with because "my husband left me for a younger woman."

Johnson, 46, considers abortion, lesbian rights and "the feminization of poverty" as the top three issues facing NOW. On abortion, her campaign literature says: "We must take an offensive rather than a reactive stance, using every strategy from speaking out about the abortions we have had, and helped our sisters have, to exploring a constitutional guarantee of reproductive rights."

She supports a constitutional amendment on gay rights.

"It is imperative that NOW's campaign for lesbian and gay rights be intensified, that it be urgent and long-term," her literature says. "We must campaign as openly, as courageously, and as powerfully for this cause as we have for any other."

She advocates that NOW use a "full range" of tactics, "from long-range planning to zap actions," to pursue its goals. "Radical is a good word," she said in an interview. "I'm not afraid to do the kind of thing you do in a civil rights movement to fight for women's rights."

"A lot of radical rhetoric is interesting," said one longtime NOW leader, who fears Johnson will win. "We were there once, but NOW has moved beyond that. We have 100,000 baby feminists and maybe she represents that group."

Although Goldsmith and Wells-Schooley refused to comment on issues in the race, their campaign letters proclaim long experience in the organization and ability to unite NOW.