Watched by more than 100 million people in the US and attracting stars including Lady Gaga, Beyoncé and Justin Timberlake, it is one of the most prestigious music shows in the world. But the Super Bowl’s half-time slot next month appears to be facing an unfamiliar problem: a lack of people willing to perform.

As the National Football League digs in its heels in a dispute with Colin Kaepernick, the star quarterback who refused to stand for the national anthem in protest at police brutality against racial minorities, the show this year has become more about politics than music. The fact that the Super Bowl is taking place in Atlanta, arguably the capital of black music in the US, has only added to the storm.

Some of the biggest names in pop and rap, including Rihanna and Cardi B, have turned down the opportunity to appear, while one group that has reportedly been booked, the Adam Levine-fronted pop-rock act Maroon 5, is facing pressure to pull out. Rapper Travis Scott, the only performer reportedly secured to join the show, is facing pressure from hip-hop superstar Jay-Z and civil rights groups to pull out. With four weeks to go, producers of the 13-minute event are scrambling to find additional performers for what Variety last week called “music’s least wanted gig”.

Gerald Griggs, vice-president of the Atlanta chapter of the NAACP civil rights group, told the Observer it had contacted performers who had signed up to ask them to rethink their participation. He said: “The majority of artists we’ve reached out to are standing in solidarity against the NFL. They do not want to be associated because of the protest that was started by Mr Kaepernick against racial injustice and police brutality.”

Kaepernick, who was the quarterback for the San Francisco 49ers and led them to the Super Bowl in 2013, accuses NFL owners of colluding to keep him out of the league after his decision to “take the knee” during the national anthem at games sparked a mass protest movement. In 2017 the player filed a collusion grievance against the NFL, claiming team owners had conspired to keep him off the field due to his protests. He is seeking damages equal to what he would have earned if he were still playing in the league. The NFL denies the allegations.

Facebook Twitter Pinterest Colin Kaepernick, right, and Eric Reid of the San Francisco 49ers ‘take the knee’ in protest during a 2016 NFL game. Photograph: Thearon W. Henderson/Getty Images

For protesters who back Kaepernick, the Atlanta show is the ideal venue to send a strong message about the league’s refusal – backed by Donald Trump – to support him and other players’ right to refuse to stand for the anthem. Trump, who was angered by the protests, said that if players refused to stand, NFL owners should “get that son of a bitch off the field right now”.

The Super Bowl half-time show – which last year was headlined by Justin Timberlake, and has previously engaged Lady Gaga and the Rolling Stones and witnessed an epic, rain-soaked performance by Prince – “is the biggest stage in the world to bring our message to the world about the atrocities that are happening in the United States, and particularly in Atlanta, that have not been addressed,” said Griggs.

“We appreciate the entertainers for lending their voices in opposition and standing with us. We call on artists like Travis Scott to pull out.”

The first star to clearly link the Super Bowl show to Kaepernick was Rihanna. In October she confirmed she had been approached to perform but had decided to support the quarterback. “She said no because of the kneeling controversy. She doesn’t agree with the NFL’s stance,” a representative told US Weekly.

“The offer and exposure would have been great for Rihanna as she’s planning a new album and tour but she stuck to what’s right in her eyes,” a source told Entertainment Tonight.

With typical flamboyance, Cardi B initially said she wanted a solo slot and $1m to perform (artists are not paid for the half-time show, but are given a “gift in kind” by the NFL), though a representative later said “she was not particularly interested in participating because of how she feels about Colin Kaepernick and the whole movement”.

Facebook Twitter Pinterest Lady Gaga performs during the half-time show in 2017. Photograph: Shutterstock

So far Maroon 5 have been absent from the conversation. The band has not been formally announced by the NFL, but a representative called the invitation “a dream come true” and its participation has not been denied.

Levine has come under pressure from comedian Amy Schumer, who has vowed not to appear in any commercial during the game, to also skip the show. “Once you witness the truly deep inequality and endless racism people of color face in our country, not to mention the police brutality and murders,” she wrote on Instagram, “why not kneel next to your brothers? Otherwise how are you not complicit? I think it would be cool if @maroon5 backed out of super bowl…”

Griggs said: “We would implore them to rethink their participation. The protest Mr Kaepernick is making over the number of people killed by law enforcement has not been resolved. We would hope they would use their celebrity status to send that message to an even broader audience by pulling out.”

The apparent decision to pass over Atlanta rappers in favour of more mainstream performers has also been criticised. Even those not directly associated with Atlanta, like Cardi B, are linked to the city through the management of the label Quality Control Music, also home to Migos and Lil Yachty.

The NFL has not commented on the controversy.