Washington — The House Armed Services Committee took a big and unexpected step toward making women register for the draft as a handful of Republicans joined Democrats on Wednesday night to back a measure whose own sponsor hoped would fail.

“Right now the draft is sexist,” said Rep. Duncan Hunter, R-Calif., who filed an amendment to the House’s annual defense authorization bill to require women between the ages of 18 and 26 to register for the Selective Service, the government agency that keeps records of who is eligible to be conscripted.

Hunter, who is against the Obama administration’s recent policy change allowing women to serve in all combat roles, said he proposed the measure only to start a discussion about the draft. He voted against his amendment, arguing that anyone who favored it would be siding with the administration.

But Hunter’s gamble that committee members would shy away from forcing women into the draft backfired when a slim majority — including five Republicans — opted to endorse the measure, 32-30.

But a measure including women in the draft still has a long way to go. It would have to survive a full House vote and then make it through the Senate.