More than a dozen Democratic lawmakers, led by Rep. Jared Huffman of California, have sent a letter to Defense Secretary Jim Mattis urging him to move forward with a policy that could start Saturday that allows transgender people to enlist.

"We strongly encourage you to deny the request of a six-month delay in transgender policy implementation," the members wrote. "Throughout our nation's history, the Department of Defense has benefited from diversity and equal opportunity programs and policies, which support recruitment, retention and promotion. There are thousands of transgender individuals in our military today. There should be no further delay in implementing this policy and allowing transgender individuals to serve the country they love."

Transgender service members have been allowed to serve openly since last year. But former Defense Secretary Ash Carter set a July 1 deadline for the four military services to write their own policies to allow individuals who already identify as transgender to enlist or receive military appointments.

Military leaders sent a request to Mattis last week asking him to delay implementation of the new policy for six months.

According to the Associated Press, the leaders said the six-month delay would give the services time to see if transgender troops currently serving are facing issues and determine if changes are needed.

The Democratic members who signed onto Huffman's letter to Mattis are: Reps. Suzanne Bonamici of Oregon, Salud Carbajal of California, André Carson of Indiana, Matt Cartwright of Pennsylvania, Pramila Jayapal of Washington, Joesph P. Kennedy of Massachusetts, Alan Lowenthal of California, Sean Patrick Maloney of New York, Eleanor Holmes Norton of D.C., Bill Pascrell, Jr. of New Jersey, Mark Pocan of Wisconsin, Debbie Wasserman Schultz of Florida, Jan Schakowsky of Illinois, Louise Slaughter of New York, Dina Titus of Nevada and Niki Tsongas of Massachusetts.