WASHINGTON — The House voted Thursday to let the Defense Department repeal the ban on gay and bisexual people from serving openly in the military, a major step toward dismantling the 1993 law widely known as “don’t ask, don’t tell.”

The provision would allow military commanders to repeal the ban. The repeal would permit gay men and lesbians to serve openly in the military for the first time.

It was adopted as an amendment to the annual Pentagon policy bill, which the House is expected to vote on Friday. The repeal would be allowed 60 days after a Pentagon report is completed on the ramifications of allowing openly gay service members, and military leaders certify that it would not be disruptive. The report is due by Dec. 1.

The House vote was 234 to 194, with 229 Democrats and 5 Republicans in favor, after an emotionally charged debate. Opposed were 168 Republicans and 26 Democrats.