(NewsNation) — Republican Rep. Nancy Mace on Monday introduced a resolution requiring all individuals in the Capitol complex to use bathrooms matching their gender assigned at birth, a move that could spark controversy as the first openly transgender House member prepares to take office.

Mace is currently working with House leadership to include the bathroom restrictions into a rules package, sources familiar with the matter say. If unsuccessful, she intends to pursue “a privileged motion,” which would allow her to bypass standard procedural requirements.

The timing of the proposed resolution coincides with Democrat Sarah McBride‘s upcoming swearing-in this January. McBride made history in November as the first openly transgender person elected to the U.S. House of Representatives.

“Never thought this would have to happen, but we are introducing a resolution banning biological men from entering protected spaces for women on Capitol grounds. Protecting biological women starts here and it starts now,” Mace wrote in a post on X.

The measure charges the House sergeant-at-arms, William McFarland, with enforcing the ban, according to text previewed by The Hill, but it is unclear how the House’s chief law enforcement officer will determine who can and cannot use the Capitol’s facilities.

State laws that bar transgender people from using public restrooms that match their gender identity often rely on anonymous complaints, a notoriously unreliable enforcement mechanism. LGBTQ+ rights activists in May flooded a tip line designed to alert officials in Utah to possible violations of the state’s bathroom ban with thousands of false complaints.

Mace is pushing for the measure to be included in the rules package for the 119th Congress, or for it to be brought to the floor and voted on as a standalone rule outside the package.

If the bill, however, is not included in the 119th Congress rules package or brought to the floor as a standalone rule, Mace would force a vote on the legislation, the source said.

The House is set to vote on a rules package for the next Congress in early January, which will require a majority vote for passage. Republicans are poised to have a razor-thin majority when the next session gavels in.

NewsNation partner The Hill contributed to this report.