A Coalition minister has called for columnist Julie Burchill and Observer editor John Mulholland to be sacked over a "disgusting rant" against transsexuals.
Liberal Democrat Lynne Featherstone condemned an Observer piece in which the journalist made a series of cutting comments about "bedwetters in bad wigs" and "shemales".
The article was penned in defence of Burchill's fellow writer, Suzanne Moore, who came under fire on Twitter after suggesting that women were expected to look like "a Brazilian transsexual".
Burchill wrote that "screaming mimis" had accused her friend of "white feminist privilege" and forced her to leave the social networking site.
A note from the Observer readers' editor was later added to the article on the newspaper website.
"As you might imagine, I have received many emails protesting about this piece this morning," the note said. "Thank you to those who have written. I will be looking at this issue and will be replying to all in due course."
Posting on Twitter last night, Featherstone - a former equalities minister currently at the Department for International Development - wrote: "Julie Birchill (sic) rant against transgender community is absolutely disgusting - a bigoted vomit for which the Observer should sack her."
In a later Tweet she suggested Mulholland should also be sacked.
A Guardian News & Media spokeswoman said: "We acknowledge the strong reaction to Julie Burchill's piece published in The Observer.
“As indicated by Observer editor John Mulholland on Twitter, we are taking such reactions extremely seriously and we have asked our independent readers' editor to urgently investigate the matter."
The newspaper's independent readers' editor is Stephen Pritchard.