US anti-gay organisations have hit back after being included on a list of ‘hate groups’.

The Family Research Council (FRC) and National Organization for Marriage (NOM) were named by a civil rights body as two of 18 groups which “demonise” gay people and propagate “known falsehoods”.

The list was compiled by the Southern Poverty Law Center (SPLC).

FRC president Tony Perkins accused the centre of slander and claimed his group always worked with ” civility and compassion”.

Calling the list a “deliberately timed smear campaign”, he added: “Family Research Council will continue to champion marriage and family as the foundation of our society and will not acquiesce to those seeking to silence the Judeo-Christian views held by millions of Americans.

“We call on the Southern Poverty Law Center to apologise for this slanderous attack and attempted character assassination.”

According to the SPLC, FRC senior research fellows Tim Dailey and Peter Sprigg have both claimed that homosexuality is linked to paedophilia and Mr Sprigg said in 2008 that there should be “criminal sanctions on homosexual behaviour”.

Another group on the list, the National Organization for Marriage, said the SPLC was trying to equate gay marriage opponents to racists.

President Brian Brown told the Washington Post: “This is about protecting marriage. This isn’t about being anti-anyone.

“The whole idea that somehow those folks who stand up for traditional marriage, like the Family Research Council, are hateful is wrong. [The law center is] trying to marginalise and intimidate folks for standing up for marriage and also trying to equate them somehow to the KKK.”

Last year, NOM was mocked by critics after it produced a video claiming that gay marriage would damage people’s rights and lifestyles.

The group was accused of peddling “outrageous falsehoods” by gay rights campaigners and tried to have its original films removed from YouTube after spoofs were made.