Andretti was the only one of four applications to the FIA’s Expressions of Interest process referred to Formula 1 for further analysis.

The FIA assessed Andretti, Rodin, Hitech, and LkySunz for their technical and financial ability to compete in the world championship.

Andretti was the only one to pass muster and progressed to the ‘next stage’ of the process, which was a commercial assessment by the sport’s commercial rights holder.

It was there that it met a roadblock, with an expansive statement detailing why the American team’s entry, which brings with it General Motors via its Cadillac brand, was refused.

Despite having had its entry blocked, Andretti has continued working towards a berth on the grid.

That includes opening a new facility at Silverstone and, earlier this week, announcing the signing of Pat Symonds – poaching him from F1 where he was its in-house technical expert.

Key bodies in the United States have also taken interest, incuding Congress and the House Judiciary Committee, which asked Liberty Media and F1 to explain how the decision is not in breach of antitrust laws.

Now, Mario Andretti, 1978 Formula 1 world champion and father of the eponymous team owner Michael, claims Liberty Media’s CEO has taken a personal interest in the matter.

Speaking with NBC, Andretti revealed he met with F1 boss Stefano Domenicali in the Palm Club during breakfast on Saturday morning at the Miami Grand Prix, where he was asked about why he’d visited Washington in the days prior.

Andretti visited Washington the week before the Miami Grand Prix, stating he was called there following a Red Bull show run near the Capitol that piqued interest in the world championship – and the lack of an American team therein.

“I was asked to go there,” Andretti said.

“And just as I was trying to explain that to Stefano, Greg Maffei, Mr. Maffei, broke in the conversation and he said: ‘Mario, I want to tell you that I will do everything in my power to see that Michael never enters Formula 1’.

“I could not believe that,” he added.

“That one really floored me. … We’re talking about business. I didn’t know it was something so personal.

“That was really — oh, my goodness. I could not believe it. It was just like a bullet through my heart.”

It’s not the first time a personal grudge has been claimed as the reason for Andretti being denied entry.

However, the NBC report added balance from an unnamed source it cited as “close to Liberty Media,” who recounted a different version of events.

While acknowledging Andretti and Maffei had a conversation in Miami, it was claimed the former made the approach with the Liberty Media CEO reaffirming that the entry had been blocked for “good business reasons.”

Among those reasons were concerns the new entry would not add sufficient value to the championship, and would not be competitive.

Andretti’s comments are the latest in an escalating situation over the team’s rejection as F1 now faces calls from senators for an investigation by the Federal Trade Commission over antitrust concerns within the sport.

A letter from the United States Senate to assistant attorney general Jonathan Kanter, and chair Lina Khan, called for action.

“We write because we are concerned that Formula One is acting at the behest of its independent teams and other “key stakeholders,” including foreign automakers, to exclude the team formed by Andretti Formula Racing, LLC’s partnership with General Motors (“Team Andretti-Cadillac”) from entering the Formula One Championship series,” the letter opened.

“It is possible that such a refusal to deal-especially if orchestrated through a group boycott-could violate U.S. antitrust laws.”

The letter went on to outline the application process and reasons for Formula One Management rejecting Andretti’s application.

“Most striking, however, was FOM’s determination that bringing Team Andretti-Cadillac into F1 would not ‘add value to the Championship’,” the letter noted.

“While F1 currently does not have an American-based team, F1 has been determined to increase its presence in the U.S. market.

“Over the past few years, more than 1 million Americans have tuned into each F1 race, more than doubling over the past few seasons.

“Last year, F1 hosted three races in America, in Miami, Las Vegas, and Austin, while no other country hosted more than a single race.

“Even individual teams, such as Red Bull, are courting U.S. fans by hosting events in U.S. cities to ‘get up close and personal with the marvel of Formula One engineering, bringing together F1 fans.’

“Clearly there is a financial incentive to adding an American team to F1’s roster, and there is no reason Team Andretti-Cadillac should be blocked unless FOM is trying to insulate its current partners from competition.”

The letter concludes: “Given these facts, we have serious concerns that the rejection of Team Andretti-Cadillac was based on a desire to exclude a rival from the racetrack, marketing opportunities, and prestige that competing in F1 can lend to a car manufacturer copetting to seel cars across the globe.

“While the FOM claims that it did not consult with current teams before rejecting Team Andretti-Cadillac, it notably references consultations with ‘key stakeholders,’ which likely include team sponsors, including car manufacturers that directly compete against General Motors and Cadillac.

“That F1 stakeholders may have engaged in concerted action to exclude Team Andretti-Cadillac-especially after it met all technical requirements to join F1-that merits investigation.”

The letter was signed by seven senators: Amy Klobuchar, Mike Lee, Gary Peters, Todd Young, Debbie Stabenow, Alex Padilla, and Mike Braun.