Rep. Trent Franks of Arizona, who asked staffers if they would bear his child as a surrogate, says he will resign

Rep. Trent Franks, an Arizona Republican who is among the most conservative members of the House, said he would resign his seat after House officials learned that he had asked two female employees to bear his child as a surrogate.

Franks’s announcement came as the House Ethics Committee said it would create a special subcommittee to investigate Franks for conduct “that constitutes sexual harassment and/or retaliation for opposing sexual harassment.”

His resignation, which Franks said is effective Jan. 31, will end the ethics investigation.

Franks said in his statement that the investigation concerns his “discussion of surrogacy with two previous female subordinates, making each feel uncomfortable.”

While Franks’s statement left the circumstances of the “discussion” murky, three Republicans familiar with the allegations said that he had asked the staffers, who worked for him at the time but have since left his office, if they would serve as a surrogate mother for his child. A spokesman for Franks did not respond to a request for comment on that claim.

In his statement, Franks said he never “physically intimidated, coerced, or had...