Rosie O'Donnell has joined gay media watchdog the Gay & Lesbian Alliance Against Defamation's (GLAAD) boycott against real-estate mogul Donald Trump.

Trump's opposition to gay rights prompted GLAAD to ask members to forgo patronizing his establishments.

O'Donnell, who is openly gay, on Tuesday announced she would not be renting at a Trump property.

"Rosie O'Donnell has sent an important message to the majority of Americans - gay and straight - who don't agree with Donald Trump's statements against marriage equality for all loving and committed couples," said GLAAD President Jarrett Barrios in a statement. "Fair-minded people should think twice about supporting a businessman who courts our dollars but advocates denying gay and lesbian couples protections that all families need to take care of each other."

The 64-year-old Trump announced he's considering a run for the White House as a Republican during an appearance at this year's Conservative Political Action Conference (CPAC).

He's mounted a campaign to win over GOP voters in early caucus states New Hampshire and Iowa, which tend to prefer socially conservative candidates.

GLAAD said Trump's opposition to gay rights – he opposes both civil unions and marriage for gay couples – is behind their decision to ask members to turn their backs on the billionaire celebrity with political aspirations.

“Trump has taken to disparaging the families of gay and lesbian couples as a tactic to get attention for his candidacy,” the group said at its Tune Out Trump campaign. “Using Trump's own famous catch phrase, we would like to tell him, “You're fired!”

The campaign asks supporters to stop patronizing Trump establishments and television shows, including many buildings in New York City, casinos in Atlantic City, Fox News' Fox and Friends and NBC's Celebrity Apprentice.