A bipartisan pair of senators Monday introduced a plan to block President Trump's transgender ban.

Sens. Kirsten Gillibrand, D-N.Y., and Susan Collins, R-Maine, introduced an amendment that would prevent the military from kicking out transgender members based on gender identity alone.

The senators plan to introduce an amendment to the National Defense Authorization Act, which is being voted on this week.

The pair previously introduced a broader amendment that would have barred the Pentagon from kicking out any transgender troops or rescinding their medical benefits until the military finished a study on recruitment and reported back to Congress.

In July, Trump announced the ban in a tweet, catching his administration— including Defense Secretary Jim Mattis — and Congress off-guard.

In August, Gillibrand tweeted, "To all trans men and women serving bravely in the military: I plan to introduce legislation to fight back. We'll keep raising our voices."

The previous plan had support from Sen. John McCain, R-Ariz., the Armed Services chairman, who will help decide which proposed NDAA amendments will be approved for a vote on the Senate floor. McCain previously said the ban was a "step in the wrong direction."

The amendment will need 60 votes to pass.