Four months after approval of the entry by the FIA, the team's bid was rejected by F1 in a lengthy statement issued on Wednesday.
The championship spelled out various reasons why it believed that the entry could not be accepted that went well beyond the commercial aspects that most observers expected F1 to cover.
One of the key assertions was that F1 felt the team had bitten off more than it could chew by planning an entry for 2025 with a car built to the current regulations, and then be obliged to follow up by having to design another for the very different rules that come into force in 2026.
F1 noted that "we do not believe there is a basis for any new applicant to be admitted in 2025 given that this would involve a novice entrant building two completely different cars in its first two years of existence.
"The fact that the applicant proposes to do so gives us reason to question their understanding of the scope of the challenge involved."
Andretti had hitherto indicated that it was still ready to enter in 2025 if the timeline allowed it but the team confirmed on Friday that internally it had already switched its focus to a 2026 debut given the lengthy entry process. That effectively nullified one of F1's key arguments.
In a statement, the team said: "When Andretti Cadillac entered the FIA expression of interest process almost a year ago, the preferred first year of participation was indicated as 2025.
"The FIA approved our application, with no specific limitation on whether the entry was for 2025 or 2026.
"Andretti Cadillac has been operating with 2026 as the year of entry for many months now.
"The technicality of 2025 still being part of the application is a result of the length of this process."
In another apparently damning revelation, F1 said: "Having had the opportunity to consider the applicant's responses together with our own deliberations, we subsequently wrote to the applicant on 12 December 2023 extending an invitation to an in-person meeting at our offices in order for the applicant to present its application, but the applicant did not take us up on this offer."
This claim appeared to question the willingness of the team to engage with F1, but Andretti Cadillac says that it did not know about the invitation.
After the F1 statement was issued, the team's IT staff found the email, which was sent by an F1 employee and not CEO Stefano Domenicali, in Michael Andretti's spam folder.
"We were not aware that the offer of a meeting had been extended and would not decline a meeting with Formula One Management," said its statement.
"An in-person meeting to discuss commercial matters would be and remains of paramount importance to Andretti Cadillac.
"We welcome the opportunity to meet with Formula One Management and have written to them confirming our interest."
The team also repeated the message included in its initial response issued on Wednesday, noting: "Our work continues at pace."
