A Roman Catholic group in America has taken out a two-page advert in three major US newspapers, calling on Christians to ‘battle for America’s soul.’

The ads were placed last week by the American Society for the Defence of Tradition, Family and Property (TFP) in the LA Times, New York Times and the Washington Post.

Using biblical quotes, the ads mostly highlight their condemnation of same-sex marriage, saying that they “cannot fulfil the primary purpose of marriage,” which is to give birth and raise children.

TFP was founded by a group of Catholic Americans in 1973 “to resist, in the realm of ideas, the liberal, socialist and communist trends of the times and proudly affirm the positive values of tradition, family and property.”

The ads are seen as an attempt to curb support for same-sex marriage.

The California courts last month ruled that same-sex marriage legal in the Golden state.

New York Governor David Paterson’s requirements for state agencies to recognise gay marriages performed legally elsewhere has also enraged the Catholics.

They see this as an attempt to push for the legalising of same-sex marriage in New York.

The report, which can be found at www.tfp.org, also claims that the California ruling violates Christian’s First Amendment rights, as they are now forced to “betray their consciences by condoning … an attack on Divine law.”

It also adds that Christians must band together to join the crusade in stopping same-sex marriage.

However, they stressed that it should be done by legal and peaceful ways, such as voting for a proposition banning gay marriage to be put to California voters in November.

So far, the LA Times has received more than 50 email complaints about the ad.

Jack Klunder, who oversees the advertising department, said on the newspaper’s blog:

“It is a long-standing policy to not reject ads simply because their message is controversial or might offend some people.

“Even though some readers may personally disagree with an ad’s position, we do not reject it solely on that basis.”