A new anti-equal marriage campaign group of conservative African American faith leaders says it will spend $1 million (£623,100) in an attempt to strip away 25% of President Obama’s support among black voters.

The lobby group called God Said plans to target black voters in the swing states of Ohio, Virginia, North Carolina, Wisconsin and Florida with radio and TV adverts.

According to the Advocate, founder Apostle Claver Kamau-Imani has denounced Mr Obama for backing same-sex marriage along with America’s oldest civil rights organisation, the NAACP, for “blindly supporting the secular views of the Democratic Party,” whose national platform “plainly supports same-sex marriage,” he added: “I am confident this message will be well received and acted upon on Election Day.”

Former Miss America contestant Day Gardner and Alveda King – the anti-gay activist niece of Dr Martin Luther King are both involved with the organisation.

In November, several US states will also hold public referendums on equal marriage legislation. Earlier this week, a group of black pastors gathered in Maryland in support of a bid to legalise equal marriage in the state, and to dispel the idea that all black ministers are against equal marriage.

President Obama’s landmark decision to announce his support for equal marriage in May of this year helped energise his re-election campaign with LGBT voters and younger parts of the electorate; however, many political commentators say it risked isolating social conservative black voters who backed his run for the presidency in 2008.

Following Mr Obama’s poor performance in last week’s presidential TV debate, Republican contender Mitt Romney, who remains deeply opposed to equal marriage and  LGBT rights in general, has erased Mr Obama’s lead in several national polls.

Mr Romney has emerged with a one-point lead over President Obama in Colorado and he has cut the president’s lead in half in Wisconsin, according to a new CBS News & New York Times poll.