A number of Republican-led states oppose new rules around transgender rights which could go against some doctors' religious beliefs

Texas and four other American states filed a lawsuit on Tuesday seeking to roll back the Obama administration’s efforts to strengthen transgender rights, saying new federal health rules could force doctors to act contrary to their medical judgment or religious beliefs.

The lawsuit is the second in recent months in which conservative states have sued over federal efforts to defend transgender rights.

Social conservatives claimed victory on Sunday when a federal judge in Texas halted an Obama administration directive requiring public schools to let transgender students use bathrooms consistent with their gender identity. Now they’re asking that same court to block new regulations intended to ban discrimination by doctors, hospitals and insurers against transgender persons.

The latest lawsuit contends that the rules, which were finalised in May, could force doctors to help with gender transition contrary to their religious beliefs or medical judgment. Transgender rights advocates called that a far-fetched hypothetical, saying a person would not approach a doctor who lacked suitable experience and expertise.

Joining Texas in the lawsuit are Wisconsin, Kentucky, Nebraska and Kansas, along with the Christian Medical and Dental Association and Franciscan Alliance, an Indiana-based network of religious hospitals.

“It discards independent medical judgment and a physician’s duty to his or her patient’s permanent well-being and replaces them with rigid commands,” the lawsuit states.

Jillian Weiss, executive director of the Transgender Legal Defence and Education Fund, said the new federal rules were groundbreaking and pointed out that other states already had similar protections. Ten states and Washington, DC, require private insurers to cover transgender health care, while six states plus the nation’s capital cover such services through their Medicaid programmes, according to advocates.

The Obama administration finalised the regulations around the time it issued its directive to public schools regarding transgender students. Thirteen states signed on to fight that directive, including three involved in the latest lawsuit, and won a temporary injunction this week from US District Judge Reed O’Connor.

O’Connor ruled that the federal anti-discrimination law known as Title IX “is not ambiguous” about sex being defined as “the biological and anatomical differences between male and female students as determined at their birth.” He also said federal officials ignored rules requiring a chance for input and feedback before new rules were implemented.

The Justice Department has not said whether it will appeal the ruling.

The new health regulations broadly affect the healthcare system because service providers who accept federal funding have to comply. The US Department of Health and Human Services referred questions about the lawsuit to the Justice Department, which declined to comment.