Roseanne Barr has said she may consider fighting the cancellation of her revival show – and even pushed an accusation that former first lady Michelle Obama masterminded the comedian’s downfall.

“I am tired of being smeared,” Barr tweeted on Thursday.

While a source told People magazine Barr is “in deep darkness and is very remorseful” for the racially-charged tweet that drew immense backlash and saw US network ABC cancel her Roseanne reboot, she seemed in a defiant mood in her latest posts.

Despite apologising for her negative comment about former Barack Obama aide Valerie Jarrett and claiming she was quitting Twitter in remorse, Barr is still using the website to fight her corner.

“I’m not a racist, I never was and I never will be,” she tweeted on Thursday (Wednesday local time).

“One stupid joke in a lifetime of fighting for civil rights for all minorities, against networks, studios, at the expense of my nervous system/family/wealth will NEVER be taken from me.”

She called for more support for her cause:

Can you all help me get more followers here? The more I have the more my words will have weight. I am a fighter 4 FAiRNESS in all aspects of US life. I am tired of being smeared-over a stupid mistake erasing 30 yrs of activism.

— Roseanne Barr (@therealroseanne) May 30, 2018

Hours earlier, the 65-year-old reportedly retweeted an online conspiracy claim from a right-wing activist that Mrs Obama had a role in Roseanne’s axing.

https://twitter.com/therealcornett/status/1001598705823346689

Barr also retweeted a post that suggested the move was payback by the Obamas after she mocked the couple’s $50 million Netflix deal with a hashtag that trended last week.

“Interesting. A few days after the popular #ObmasNetflixShows was all over the place making people giggle. Not surprised and I would not doubt it being very true”, Barr shared with her 809,000 followers.

https://twitter.com/therealroseanne/status/1000828565896679424

Abandoning her contrite apologetic position from Tuesday, Barr sensationally revealed the positive feedback she’s getting from some users makes her feel bold enough to challenge the ABC.

“You guys make me feel like fighting back. I will examine all of my options carefully and get back to you,” she wrote.

It’s not known what the terms of Barr’s negotiations with ABC were when it revived her ’90s sitcom, but standard practice reportedly dictates that a morality clause is included in an actor’s contract.

This gives an employer the power to sack a public figure if they commit a crime or tarnish a brand, although it has been reported Barr might find a way to litigate for wrongful dismissal.

Even as Barr was mounting her own fightback, she was issued an epic unexpected smackdown.

After deleting the tweet that started the brouhaha she said her comments were influenced by the use of prescription sleeping drug Ambien.

“Not giving excuses for what I did but I’ve done weird stuff while on ambien-cracked eggs on the wall at 2am etc.”

Sean Penn admitted during a shambolic appearance on Stephen Colbert’s talk show in March he was “a little bit” on the “Ambien train”, and the drug also reportedly caused problems for Elon Musk and Tiger Woods.

The company’s maker Sanofi issued a short rebuttal: “Racism is not a known side effect”.