TUV leader Jim Allister has hit out over a news article that described four-year-old Prince George as a "gay icon".
The article appeared in PinkNews at the end of last month and discussed the prince's outfit and how he looked "fabulous".
MLA Allister said the article was "misjudged" and "sick". However, the publication has rejected Mr Allister's claims.
"In reality the photo which prompted the piece shows a four-year-old boy who is smartly dressed and excited about being on a helicopter with his male father and female mother," said Mr Allister in a letter to the LGBT publication.
"To take an image of a little boy and to fantasise of him being an icon for a life defined by sex is outrageous and sick.
"Sexualising a young child in this fashion is entirely inappropriate. You should immediately withdraw the article and apologise."
Mr Allister said there was a backlash to the article on the publication's own Facebook page. He also criticised the publication for not being a member of regulator IPSO. However it only regulates newspapers and PinkNews has participated in consultations on how online only publications can be regulated.
In a statement, he added: "With multiple media outlets clearly obsessed with LGBT issues I find it amazing that this inconvenient article has been completely ignored. While anyone who dares to challenge whatever the latest demand of the LGBT lobby is will be subject to scrutiny this grossly offensive article has passed without comment.
PinkNews rejected that it was "sexualising" the child, but rather that it was highlighting social media reaction to the picture. The article did state it "isn't about his sexuality".
"As Madonna, Lady Gaga, the Babadook and yes, even Ariana Grande have shown, you don’t have to be gay or even have a defined sexuality to be an LGBT icon," the article said.
"And if some want to view Prince George in that light – even humorously – in a culture which isn’t exactly overwhelmed with LGBT representation, it’s hard to see what’s wrong with that."
The article, however, does state that it had been edited "to provide greater clarity". The organisation said this was "minor" and involved moving a paragraph higher up the article.
Benjamin Cohen, chief executive of PinkNews said he had not yet received the letter from Mr Allister.
"I’m surprised that Jim Allister is such an avid reader of PinkNews that he spotted a minor article from three three weeks ago to complain about today," he said.
"At no point did PinkNews state that Prince George is a 'gay icon'- the article merely reported on a large volume of social media posts saying that he was. The article also explored what it means to be a gay icon and referenced other ‘gay icons’ such as the pop singer Ariana Grande.
"Mr Allister also appeared to claim that being gay is a 'life defined by sex'. This is an outrageous statement. I am gay and about to marry fiancé, and I can certainly say that my life is not defined by sex."