Grace Slick has been threatened with a “death sentence” for the sin” of donating royalties to LGBT charities by Franklin Graham, the pastor who preached at Donald Trump’s inauguration.

The Jefferson Airplane and Starship star gave the money she earned from having one of her songs used in an advert for food chain Chick-fil-A to LGBT rights charity Lambda Legal, in protest at the chain’s multi-million-dollar donations to anti-gay groups such as the Family Research Council and Exodus International.

Graham, who has previously called gay people “the enemy” and praised Vladimir Putin’s anti-gay legislation, wrote on Facebook: “She certainly has the right to do that, it’s her money, she earned it [but] what I want Grace and others to know is that Almighty God created and defined marriage in His Word.

“Any sexual relationship outside of marriage between a man and a woman is sin, and all sin carries a death sentence.”

Slick had previously explained her move in Forbes magazine. “I firmly believe that men should be able to marry men, and women women,” she wrote. “I am passionately against anyone who would try to suppress this basic human right. So my first thought when ‘Check’-fil-A came to me was, “Fuck no!”… but then I decided, “Fuck yes.”

She continued: “Instead of them replacing my song with someone else’s and losing this opportunity to strike back at anti-LGBTQ forces, I decided to spend the cash in direct opposition to ‘Check’-fil-A’s causes – and to make a public example of them, too. We’re going to take some of their money, and pay it back… I hope more musicians will think about the companies that they let use their songs; we can use our gifts to help stop the forces of bigotry. Nothing’s gonna stop us now.”