Gay rights campaigners in Rhode Island are urging the state’s governor to veto a civil unions bill because they say it contains “dangerous” and “discriminatory” language.

The bill is expected to be passed by the Senate this week but campaigners are deeply concerned about some of the religious provisions within it.

One clause allows any religious body – including faith-run schools, hospitals and cemeteries – to disregard civil unions. The clause says they – or their employees – cannot be fined or penalised for failing to recognise civil unions or provide goods and services in relation to civil unions.

Gay rights activists say the “dangerous” and “discriminatory” amendment will have severe consequences for gay people, who may find they are barred from making medical decisions for spouses if faith-run hospitals decide not to recognise civil unions.

It was tabled by Democrat representative Arthur J Corvese, who is against gay marriage.

Yesterday, Marriage Equality Rhode Island (MERI) and nine other equality groups wrote to governor Lincoln Chafee: “The bill put forth by the legislature would create onerous and discriminatory hurdles for same-sex couples that no other state has ever put in place. As a result, we ask you to veto the bill should it come to your desk in its present form.”

The letter adds: “By allowing individuals and institutions a free-floating licence to discriminate against a whole class of people, in defiance of a general law, this bill represents a huge step backward from both Rhode Island’s longstanding nondiscrimination commitments and the balance and language embraced in the law throughout the country.

“This amendment could allow individuals, who are legally required to recognise everyone else’s legal commitments, to opt out of doing so only for gay and lesbian people.”

This week, 14 lawmakers wrote to Mr Chafee to argue the same point. The governor is in favour of gay marriage.

Earlier this year, gay rights campaigners pushed for progress on gay marriage but House Speaker Gordon Fox – who is gay – said there was not enough support.

Five states – Massachusetts, Connecticut, Iowa, New Hampshire and Vermont – and the District of Columbia – currently allow gay couples to marry.

In several weeks, gay couples will begin marrying in New York after a bill was signed by Governor Andrew Cuomo last week.

Recent national polls have found that just over half of the population support marriage equality.