BOSTON--In flare-ups forcing colleges to choose between religious freedom and gay rights, Tufts University and Middlebury College are embroiled in debates over whether to punish evangelical Christian student groups that refuse to allow gay students to hold leadership posts.

An arm of the Tufts student government has already sharply limited the rights of the Tufts Christian Fellowship, banning the group from using the Massachusetts school's name, meeting in its classrooms, spending its student-activity fees, or promoting its events through the university's listing services.

In Vermont, students, faculty, and administrators are debating whether to require the Middlebury Christian Fellowship to allow gays to hold leadership posts, a step the evangelical group says would force them off campus.

Meanwhile, in Iowa, evangelical students at Grinnell College are hoping to regain recognition after they were stripped of their status as an official student group for insisting that student leaders agree that sex should be engaged in only by heterosexual married couples.

Civil libertarians are irate at what they describe as an increasing willingness at private colleges to discriminate against evangelical Christians.

"What Tufts and Middlebury are really saying is that the view that the Bible takes is an illegitimate view, and you can get thrown off campus for it," said Elliott Abrams, a former assistant secretary of state for human rights. He is now president of the Ethics and Public Policy Center in Washington. "That's bigotry. The message being sent by these schools to evangelicals is, 'If you're really serious about your beliefs, why don't you go to Bob Jones University and not here?'"

A similar point was made by Harvey A. Silverglate, a Boston civil rights lawyer who helped establish the Foundation for Individual Rights in Education, a Philadelphia-based organization assisting the Tufts evangelicals.

"Orthodox Christians and Catholics have a really hard time on liberal arts campuses today, and the reason for that is that so many of their views conflict with the prevailing notion that there should be equality for gays and equality for women," Silverglate said.

But gay rights advocates say college groups should not be able to use student fees to discriminate.

"They should abide by the non-discrimination policies of the universities," said David Smith, communications director for the Human Rights Campaign, a Washington-based gay rights group. "It's our belief that religion should never be used to justify discrimination against gay people in public settings."

The dispute at Tufts, located just outside Boston, began when Julie Catalano, a junior psychology major who had been active in the Tufts Christian Fellowship since her freshman year, told leaders of the evangelical group that she wanted to be one of several student senior leaders next year. But one group leader made it clear to Catalano that she would be ineligible for a leadership post because of her belief that homosexual activity is not wrong.

Catalano, a member of the United Church of Christ who hopes to attend divinity school, said that after praying unsuccessfully to Jesus to make her heterosexual, and after contemplating suicide, she decided that her homosexuality could not be changed, nor was it sinful.

Catalano quit the evangelical group and challenged its right to use student fees.

The Tufts student government, declaring that the Tufts Christian Fellowship was violating a university policy barring discrimination on the basis of sexual orientation, declared the group "derecognized."

As a result, the group is not supposed to use the word "Tufts" in its name, can no longer hold its prayer meetings or Bible discussions in classrooms, cannot use its $6,000 annual stipend from student government, and cannot publicize its activities through the listing services available to recognized student groups.

"I'm not challenging their right to hold their beliefs, nor am I challenging their freedom of association, but I don't think pulling their recognition or funding violates either of those two constitutional rights," Catalano said. "They can still hold their beliefs and hold their meetings, but Tufts has a right to say, 'No, we will not fund you because you're in violation of university policy.'"

But the evangelical students, who are appealing the student-government decision to a student-faculty committee, say they should not be forced to promote to leadership someone who doesn't share their religious beliefs. They warn that the decision sets a dangerous precedent, because Muslims, Catholics, and Orthodox Jews all have views on gender and sexual orientation that could be viewed as discriminatory.

"We welcome members of any sexual orientation to be members of our group, but don't take a sledgehammer to our religious principles," said Curtis Chang, an affiliate chaplain at Tufts and the Boston-area director of InterVarsity, an umbrella organization of college evangelical groups.