Apple has approved an iPhone app which calls on users to sign up to a declaration against LGBT rights and gay marriage.

The app is based on the Manhattan Declaration, a manifesto released in 2009 by Christian and Catholic leaders which rails against the “erosion” of marriage.

Apple has given the app a 4+ rating, meaning that it contains “no objectionable content”.

The app asks users whether they agree with four statements on abortion and same-sex marriage and those who answer that they are pro-choice and pro-gay marriage are told that they are incorrect.

It also has links to read and sign up to the full declaration, which says that gay relationships are “immoral” and that same-sex marriages are equivalent to sanctioning incest.

The declaration says that signatories act out of “love and “concern for the comment good” rather than prejudice.

One US gay rights group is calling for people to sign a petition to ask Apple to remove the app.

Change.org said: “Apple, for their part, has given the app a rating of 4+. What does that means? According to their rating system, it means that the app contains ‘no objectionable material’. Say what?

“Because it sure seems like if you’re going to call same-sex relationships ‘immoral sexual partnerships’, or if you’re going to accuse gay people of ‘eroding marriage’,or if you say that gay people don’t deserve basic civil rights, that should at least fall into the category of ‘objectionable’.”

Apple could not be reached for comment and a return email said the company’s offices were closed for Thanksgiving.