Sources suggest that the 10 current teams want the anti-dilution fee to be boosted to at least $600m, with one team principal telling Autosport that it was the lowest figure that has been mentioned, and that it could go higher.

If agreed the new number could force Michael Andretti to reconsider his plans to enter with General Motors brand Cadillac, which are built around the current figure.

Andretti still has the option to buy an existing team, having previously been turned down by Sauber and others.

Intriguingly the potential entry fee hike comes just as it has emerged that Red Bull’s bosses are considering the future of AlphaTauri, with options including putting it up for sale or retaining it and moving it to the UK.

Andretti is known to have enquired about buying the Italian outfit in the past, and those discussions could now restart.

Red Bull’s price is likely to be well above the potential $600m cost of a new entry, but Andretti would have a good starting point with the Faenza factory and the UK-based aerodynamic department – and would not be compensating its rivals.

The original $200m anti-dilution fee was agreed as part of the current Concorde Agreement, which was signed in August 2020 and covers the 2021-25 seasons. It guarantees a one-off payment of $20m from any new entrant to each of the 10 existing teams.

It was intended to cancel out the potential loss of prize money for the current teams on the basis that a newcomer could have entered as early as 2022, and thus taken a share of the total prize fund for the last four seasons of the Concorde Agreement.

Having failed to find a way into F1 by buying an existing team, Andretti switched his focus to starting from scratch and gaining a new entry. He is thus prepared to make the $200m payment and enter as early as 2025, the final year of the Concorde.

The door for new entries was formally opened in January by the FIA when it announced a call for expressions of interest for an entry in 2025, 2026 or 2027, as the first stage in the process. Three potential teams are understood to have made that step, with Andretti joined by Hitech and Panthera Asia.

The anti-dilution fee will only become relevant if a prospective team passes all the checks and is provisionally accepted by the FIA. If that happens it is set to become a major point of debate because, as Andretti’s bid gathered momentum last year, existing teams made it clear that they believed that the current $200m fee was no longer enough.

The number was agreed in the summer of 2020 at the height of the COVID pandemic, with the delayed F1 season just getting under way and races held without spectators.

At the time several teams were under severe financial pressure, and there were genuine fears that one could be lost, and some were actively looking for new buyers or investors. The sale of Williams to Dorilton that summer also created a ballpark figure for the value of a team at the time.

Over the past three years the situation has changed dramatically, with the cost cap reducing expenditure and interest stirred by Drive to Survive helping to increase income for the teams, all of which are now in a healthy position, with some turning away potential buyers.

The values of the current teams have been boosted dramatically, and they are wary of the impact that an 11th entrant could have.

Publicly the common line from team bosses is that they trust the FIA and F1 to conduct a fair entry process and determine whether any of the bids is viable, and they stress that any new entrant must bring something to the championship.

However while Andretti’s bid was seemingly strengthened by the announcement of a GM/Cadillac partnership, behind closed doors rival teams remain determined to keep the field at 20 cars with the manufacturer support widely-dismissed as a badging exercise.

From 2026 there will be a new Concorde with an inevitably much larger anti-dilution fee built in, which explains why Andretti wants to come in in 2025 and thus run one season under the current engine formula. However the existing teams also want to change the 2025 fee as agreed in the current Concorde, despite the entry bid process having already got underway.

A procedure for such a change exists, and the 10 current teams and the F1 organisation would have to agree unanimously to increase the fee. After months of debate, it appears that such a move is close to happening.

While Andretti has made it clear that he has clear that he is willing to spend the $200m, it remains to be seen how he and his investors will react if suddenly presented with the higher number. There could even be a legal challenge to such a change, which might be regarded as a barrier to entry.

The anti-dilution fee is technically related to the potential loss of prize money resulting from the addition of an 11th team, whereas the existing teams are linking it to the potential overall value of an entry. The $600m figure is believed to reflect the most recent deal, the sale of Sauber to Audi, and is likely to be a point of contention.