"Just say no!" is back again, but the forbidden fruit this time isn't drugs — it's sex.

President Bush will ask Congress to raise funding for abstinence-only education by 33 percent. That increase, to a total of $135 million, would go into making sure young Americans are all "good girls and boys" in 2003, according to an administration official who spoke Wednesday on condition of anonymity.

But it's up for debate whether that extra $33 million could be better spent on responsible sex. Though spending on abstinence-only teaching has been climbing over the last five years and conservatives argue that contraception education implicitly condones teen sex, critics say abstinence programs are impotent when it comes to stopping kids from doing the deed.

"I find it stunning that an administration that touts the values of science when it comes to environmental policy can't run fast enough away from science when it comes to sexual health," said James Wagoner, president of Advocates for Youth.

His group supports "abstinence-plus" programs, which encourage teens to say no to sex but suggest contraceptives and condoms for those who do not.

Health and Human Services Secretary Tommy Thompson, while noting that the programs are very popular with many of his Republican colleagues, acknowledged that no one knows if they really work. But he said the programs should be given a chance.

"The president feels, the administration feels, a lot of people in Congress feel that this is a much better way to attempt to solve this problem of teen-age pregnancy," he said Wednesday. "Let's try them out and see if we can't get it to work."

When the extensive research under way comes to a conclusion one way or the other, that's when Thompson said he'll decide whether to cut funding for abstinence programs.

"I'm a results-oriented kind of person," he said.

According to the administration official, the Bush budget will ask Congress for abstinence-only money in three pieces:

$50 million in grants to states through welfare programs. The welfare law, which included automatic funding for the abstinence program each year, must be renewed this year. Bush will propose that the program remain at $50 million, at least for the first year. This request will be considered as part of the larger debate over what changes are needed in the welfare law.  Proposals to modify the abstinence program appear certain.

$73 million, an increase of $33 million, in competitive HHS grants.

$12 million, the same as this year, for the Adolescent and Family Life program, which provides money to states to work with teen mothers.

With the request, Bush is standing by a pledge he made while campaigning for president. He promised to spend as much promoting abstinence as some have calculated the government spends educating teens about contraception.

Proponents argue that the nation has spent considerable money on birth-control services, yet nearly 900,000 teen-agers get pregnant each year and one in three American babies is born to unmarried parents.

Under the abstinence-only welfare reform law, state programs must meet one of eight goals. Among them: teaching that sex outside marriage probably would have harmful psychological and physical effects; how to reject sexual advances; and why drugs and alcohol make avoiding sex more difficult.

Uncomfortable with the program, many states used their money to run pro-virginity media campaigns or after-school programs that make little if any mention of sex or abstinence.

Conservatives in Congress complained that states were dodging the intent of the program, so they created a new pool of abstinence-only money distributed directly by HHS. This program, which is where Bush wants the money increase, is meant to pay for programs that overtly discuss the value of avoiding sex.

The Associated Press contributed to this report.