Fired Guardians of the Galaxy director James Gunn is unlikely to be reinstated, industry sources have said, just days after reports production bosses were considering letting him return after a show of support from fellow cast members.

Gunn was dismissed on July 20 after tweets resurfaced from almost a decade ago in which he joked about rape and pedophilia, prompting all nine of the film franchise's stars to sign an open letter on Monday calling for the director to return.

But speculation Gunn was on his way back appears to have been quashed by a new report from Variety on Wednesday, which quoted 'multiple people close to the studio's thinking' who said he was unlikely to be reinstated.

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The Guardians of the Galaxy cask are pictured, from left to right at the Eventim Apollo in London on May 24: David Bautista, Zoe Saldana, Pom Klementieff, Chris Pratt, Kurt Russel, Karen Gillan, James Gunn and Michael Rooker

Gunn (pictured in California on May 25) was dismissed on July 20 after tweets from almost a decade ago where he joked about rape and pedophilia resurfaced

The publication of the open letter and a coinciding pro-Gunn petition signed by 300,000 fans, also on Monday, led to immediate speculation Disney and Marvel were about to cave into pressure.

In a report published that same day, Variety quoted industry sources saying there was a 'growing feeling' he would be allowed to join the series' third film, due to be released in 2020.

The sources now say Disney have come to the conclusion that the dozens of tweets Gunn made from 2008 to 2011 are unacceptable in the #MeToo era and out of kilter with the company's family-friendly image.

'I don't see Disney re-hiring him,' one person close to Disney's thinking said.

'Those tweets were so horrible and Disney has a different standard than other studios.'

Walt Disney chairman Bob Iger is on vacation so any decision on a new director or reinstating Gunn may have to wait until he's back next week.

The letter was signed by nine of the movie's main characters: Pratt, Cooper, Saldana, Vin Diesel, Dave Bautista, Sean Gunn, Pom Klementieff, Karen Gillan and Michael Rooker

Gunn's current Twitter account is heavy on left-leaning politics, and alt-right agitators with whom he'd sparred found and promoted the tweets that led to his firing.

They included messages such as, 'The best thing about being raped is when you're done being raped and it's like 'whew this feels great, not being raped!'' Others made fun of the Holocaust, 9/11 and AIDS.

The cast on Monday said it fully supported Gunn and the character he showed both on the set of the first two movies and in the wake of his firing.

Chris Pratt, Zoe Saldana, Bradley Cooper, Vin Diesel and the other five stars said they waited 10 days to issue a statement to 'think, pray, listen, and discuss'.

'Each of us looks forward to working with our friend James again in the future,' the cast members wrote, expressing that they were all shocked by the firing.

Gunn had directed the first two movies in the Guardians of the Galaxy franchise. He is pictured at the premiere of the original film in 2014 with lead actors Saldana and Pratt

Pratt (pictured with Gunn at a photo call in Tokyo on April 11) posted the letter of support to his Instagram account and wrote in the caption: 'Although I don't support James Gunn's inappropriate jokes from years ago, he is a good man

Pratt added in an Instagram post that he would 'personally love to see him reinstated as director of Volume 3'.

'Although I don't support James Gunn's inappropriate jokes from years ago, he is a good man,' Pratt added.

The letter also discusses the climate that led to Gunn's abrupt firing and the lack of 'due process in the court of public opinion'.

'James is likely not the last good person to be put on trial,' the cast members continued.

'Given the growing political divide in this country, it's safe to say instances like this will continue, although we hope Americans from across the political spectrum can ease up on the character assassination and stop weaponizing mob mentality.'

Gunn's brother Sean, who plays a character in the franchise, has said working on Guardians has made the director a better person. Left to right: Gunn, Bradley Cooper, Benicio del Toro, Michael Rooker and Sean Gunn attend the premiere of the first installment in 2014

Gunn has been writer and director of the 'Guardians of the Galaxy' franchise from the start, taking an obscure Marvel Comics title about a group of multi-colored misfits and turning it into a space opera decked with comedy and retro music that made Pratt a major movie star.

Through two instalments the franchise has brought in more than $1.5billion in global box office, and much has been staked on the third film that would launch another decade, or more, of Marvel films.

Disney and Marvel declined to comment on Wednesday's report.