Donald Trump is under fire from LGBT advocates for his and Florida Sen. Marco Rubio’s decision to attend what they consider an anti-LGBT event just miles from Pulse nightclub in Orlando, where a gunman claimed the lives of 49 people at the reputedly gay venue in June.

Adding insult to injury, the gathering is set to take place on the two-month anniversary of the shooting.

“Just when you think Donald Trump and Marco Rubio couldn’t go any lower, they announce plans to court anti-LGBTQ activists in Orlando,” the Human Rights Campaign, the country’s largest LGBT group, said in a statement on Tuesday.

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Prominent gay activist Danielle Moodie-Mills, who’s done consulting work for GLAAD, told TheWrap, “This is a through and through anti-LGBT event that they want to downplay. It should put everyone LGBT and straight on notice.”

Jim Key, Chief Marketing Officer of the Los Angeles LGBT Center told TheWrap that, “after his disingenuous flirtations with LGBT people at the Republican National Convention, it will be fascinating to see what Trump has to say about us in a room full of anti-LGBT evangelicals.”

And Right Wing Watch, a group dedicated to monitoring and reporting on the activities of right-wing political organizations, called the event an “extremist Anti-LGBT Summit.”

The gathering, “Rediscovering God in America,” is being hosted on Thursday by the Florida Renewal Project. The news of Trump’s involvement comes just one week after LGBT activists slammed Rubio for agreeing to be the event’s keynote speaker. Rubio recently cited the Orlando shooting as the reason he reconsidered his decision not to run for re-election to the Senate.

“I’ve been deeply impacted by it and I think when it visits your home state, when it impacts a community you know well, it really gives you pause,” he told conservative radio host High Hewitt in June.

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For his part, Trump has been flirting with religious conservatives on the campaign trail, promising to repeal the Johnson Amendment, which prohibits churches from using tax-exempt resources to promote political candidates.

David Lane, founder of the American Renewal Project, told Bloomberg on Tuesday that repealing the Johnson Amendment was “a good first step,” adding he was eager to hear more from Trump about his opposition to LGBT rights.

What concerns LGBT groups is the event’s roster of speakers, which includes David Barton, a Republican Party activist who has said that God is justly preventing a cure for HIV/AIDS because it is a divine “penalty” for homosexuality; co-founder of Liberty Counsel Mat Staver, who’s organization defended Kim Davis, the Kentucky county clerk who gained notoriety last year after refusing to issue marriage licenses to same-sex couples; Ken Graves, a Maine pastor who believes gay people “seek to take over our land and make it Sodom;” and Bill Federer, a religious conspiracy theorist, who said gay rights are bringing about the “Islamist takeover of America.”

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Rubio has defended his decision to appear at the Christian conference, telling the Tampa Bay Times in a statement last week,”Leave it to the media and liberal activists to label a gathering of faith leaders as an anti-LGBT event. It is nothing of the sort. It is a celebration of faith.”

But LGBT activists say that’s hogwash.

“What this summit shows is that that the hate against the LGBT community is deep and these folks don’t want to just preach from the pulpit but create policy to justify their prejudice,” Moodie-Mills said.

Trump’s campaign did not respond to TheWrap’s request for comment.