More than 150 House Democrats signed a letter sent to U.S. Department of Health and Human Services (HHS) Secretary Robert F. Kennedy Jr. on April 3, calling for the department to undo the freeze on millions of dollars allocated for family planning services.

The letter, shared exclusively with TIME, comes after HHS confirmed this week that it is withholding Title X funds from 16 organizations “pending an evaluation of possible violations” of federal civil rights laws and President Donald Trump’s Executive Order declaring that undocumented immigrants are barred “from obtaining most taxpayer-funded benefits.” Title X is the nation’s only federally funded program dedicated solely to family planning, and each year allocates millions of dollars for clinics that provide birth control, cancer screenings, STI testing, and other health care services for people from low-income households. HHS did not respond to TIME’s questions earlier this week about the details of the “possible violations,” how much money was being withheld from the affected organizations, and which organizations were being hit by the funding freeze. It also did not respond to a further request for comment today, April 3.

More than $200 million is allocated for Title X annually. On March 25, the Wall Street Journal reported that HHS was considering freezing $27.5 million of those Title X funds. One of the largest Title X providers, Planned Parenthood, said on March 31 that nine of its affiliates were informed by the federal government that their Title X funding was being withheld as of April 1.

Read More: Trump Administration Freezes Critical Title X Funding for 16 Organizations

The letter sent to Kennedy on April 3 was an effort led by seven House Democrats: Rep. Judy Chu, California; Rep. Diana DeGette, Colorado; Rep. Ayanna Pressley, Massachusetts; Rep. Teresa Leger Fernández, New Mexico; Rep. Lizzie Fletcher, Texas; Rep. Sharice Davids, Kansas; and Rep. Nikema Williams, Georgia. The 162 House Democrats who signed it said in the letter that Title X has been “a cornerstone of safety-net care” for decades.