In a radio advertisement aimed at religious conservatives, the Clinton campaign is showcasing the President's signature on a bill banning gay marriages in spite of earlier White House complaints that the issue amounted to ''gay baiting.''

The advertisement also promotes President Clinton's work to protect religious freedom and says he wants ''a complete ban'' on late-term abortions ''except when the mother's life is in danger'' or when a woman ''faces severe health risks.''

It refers to Mr. Clinton's support of the Defense of Marriage Act, which the President signed into law last month, to the dismay of many gay rights advocates. Mr. Clinton signed the law early on a Saturday morning, minimizing news coverage. He said he had long agreed with the principles in the bill but hoped it would not be used to justify discrimination against homosexuals.

The White House spokesman, Michael D. McCurry, had earlier criticized Republicans for raising the issue, calling it ''gay baiting.''