Colorado Gov. John Hickenlooper joined 13 other Democratic governors Thursday in issuing a letter urging the Trump administration to reconsider proposed changes to Title X, a federal grant program that funds family planning and preventative health care.

“As governors representing 90 million Americans, we are deeply concerned with this administration’s plan to undermine women’s health and place sweeping new restrictions on reproductive healthcare providers across our country,” the governors wrote in the letter, addressed to U.S. Department of Health and Human Services Secretary Alex Azar.

“This dangerous proposal would upend decades of bipartisan cooperation, taking away women’s healthcare through trusted medical providers like Planned Parenthood and eroding their access to comprehensive, medically accurate information.

> Related: Trump remaking federal policy on women’s reproductive health

“We strongly urge you to reconsider this plan, which is nothing more than a domestic ‘gag rule’ that poses serious risks to women’s health.”

You can read the letter here.

Most of the changes involve rules and regulations under the administration’s direct control, such as a proposal to forbid federally funded family planning clinics from referring women for abortions and separately allowing more employers who cite moral or religious reasons to opt out of no-cost birth control for women workers.

A recently proposed rule would make major changes to Title X, including banning clinics from sharing physical space and financial resources with abortion providers. Providers like Planned Parenthood could be forced out.

If such changes are imposed, “we will have no choice but to explore all possible avenues, including legal options,” the governors wrote.

Title X serves about 4 million low-income people, mainly women. Disruptions could affect women’s access to long-acting contraceptives, such as implants and IUDs. Those are more effective than daily pills that can be forgotten, but also much more expensive up-front.

Eight professional groups representing doctors, nurses, midwives and physician assistants say the administration’s Title X proposal “dangerously intrudes” on the patient-provider relationship.

The administration says it supports family planning and isn’t cutting funding – merely drawing a “bright line” between birth control and abortion. Officials say the doctor-patient relationship is protected because if a woman asks for an abortion referral, Title X doctors could offer a list of pregnancy services providers, including some who perform abortions.

Abortion is legal, but under longstanding law and regulations, taxpayer money cannot be used to pay for abortions. Planned Parenthood, a major provider of both kinds of services, can receive federal family-planning grants while separately providing abortions.

Social and religious conservatives praise the administration for promoting “a culture of life.” But women’s rights activists and some medical experts view the multi-pronged changes as a dangerous ideological shift that could increase unintended pregnancies and abortions.

“When I ran for office, I pledged to stand for life,” President Donald Trump said in a recent speech to the Susan B. Anthony List, which backs political candidates who oppose abortion. “And as president, that’s exactly what I’ve done. And I have kept my promise, and I think everybody here understands that fully.”

The governors of Washington, Rhode Island, New York, Minnesota, Connecticut, Montana, Hawaii, Pennsylvania, Oregon, Delaware, North Carolina, New Jersey and Virginia also signed the letter.

The Associated Press contributed to this report.