gov. phil bryant
© Rogelio V Solis/APThe law is awaiting the signature of Mississippi's Republican governor Phil Bryant
Gay people could be turned away by hotels, restaurants and pharmacies across Mississippi thanks to an expansive new religious freedom law approved by the state legislature, civil liberties campaigners have warned.

Under the Religious Freedom Restoration Act, which was abruptly taken up and passed by state legislators on Tuesday, Mississippi authorities are banned from placing a "burden" - such as the threat of legal action - on "a person's right to the exercise of religion".

The law, which is awaiting the signature of Republican governor Phil Bryant, was hailed as a triumph by socially conservative groups such as the Family Research Council, which opposes efforts to ensure that "homosexuality be accepted as equivalent to heterosexuality in law".

"This is a victory for the first amendment and the right to live and work according to one's conscience," Tony Perkins, the group's president, said in a statement. "This common-sense measure was a no-brainer for freedom."

However, campaigners for gay rights and other civil liberties warned that the measure was little more than a carefully worded version of a law vetoed in Arizona earlier this year by governor Jan Brewer, which more explicitly gave businesses the right to decline gay customers.

The Mississippi law specifies that "exercise of religion" includes "the ability to act or the refusal to act in a manner that is substantially motivated by one's sincerely held religious belief". It allows state authorities to jeopardise this only when they have an "interest of the highest magnitude that cannot otherwise be achieved".

Analysts for the Human Rights Campaign (HRC) said that pharmacists in Mississippi would be entitled under the new law to refuse to provide hormone replacement therapy drugs or even HIV medication to people whose sexual orientation offended their religious standpoint.

Same-sex couples planning to marry could be blocked from tailors and outfitters, bakeries and wedding venues, the group said, while restaurants, inns and hotels could "potentially turn away same-sex couples celebrating an anniversary, adoption or pregnancy".

The HRC's state legislative director, Sarah Warbelow, said the law would "hollow out" legal protections against discrimination and urged Governor Bryant to veto it. "While there were many efforts to correct the clearly problematic elements of this legislation, the bill still has the effect of making LGBT people strangers to the law," Warbelow said in a statement.

The law, which also adds the words "In God We Trust" to the state seal, will come into effect on July 1 if signed by the governor. It comfortably passed both the state house and senate on Tuesday, with opposition lodged by a minority of Democrats. Citing Mississippi's past opposition to civil rights legislation, David Blount, a state senator for Jackson, warned colleagues: "We don't have a lot of good will out there in the country to fall back on when it comes to a record against discrimination," according to the Associated Press.

The law's sponsors boasted during debate that their measure had been endorsed by business groups in the state. Opposition to the Arizona law from industry groups, who said they feared that discrimination against gay people would be bad for business, was cited as an important factor in Governor Brewer's decision to use her veto.

Some civil rights campaigners said they were confident that any discrimination of LBGT people that occurred under the Mississippi law would eventually be ruled illegal by a judge. The protection against such discrimination could be deemed a compelling enough purpose for state authorities to "burden" the religious beliefs of business owners.

"We remain hopeful that courts throughout the state will reject any attempts to use religion to justify discrimination," Jennifer Riley-Collins, executive director of the American Civil Liberties Union of Mississippi, said in a statement. "Nobody should be refused service because of who they are."