The FIA has approved Andretti’s new team bid meaning the American entry, working with General Motors firm Cadillac, must now seek approval from series rights holder FOM.
However, there is resistance from the 10 incumbent teams who fear any destabilising effect that a new entry might have and oppose having to reduce their commercial income by 10%.
Williams team principal Vowles has clarified that his squad is strongly against the expansion of the grid until a time when all competitors are financially stable, which he says is some way off.
“My thoughts are very clear. Williams is against the addition of an 11th team and very strongly against,” Vowles said.
“My responsibility is to 900 employees within my company. You’ll see that we’re [losing money].”
MORE: How the FIA went from seven F1 new team bids to Andretti
According to recently released accounts listed on Companies House, Williams Grand Prix Engineering Limited posted a post-tax loss of £17.9m for 2022.
Vowles continued: “The reason why is we’re investing in the sport to become better. We believe in where the sport is going, we believe in the direction of travel of the sport.
“The reason why is we actually have, I think, a sustainable entity for once. Teams are actually working more and more together; we have close racing as a result of things.
“But it should be known that this isn’t just us that are not financially stable. I would say probably half the grid aren’t.
“I think the addition of an 11th team is a sensible thing but only at the point where the 10th team on the grid is financially stable.
“Everyone says we’re in a good place. We are in some regards but now… hundreds of millions [are] being invested to make the sport better.
“It becomes therefore clear why we’re very careful about diluting what we’ve already got because it's just more losses on the table.”
Despite this strong opposition to an extra team, Vowles said F1 should welcome an OEM like General Motors with “open arms”.
He continued: “We’ve been clear from the beginning, more than happy to bring in new entities but the pie has to grow as a result of it, not shrink. So far, it’s just shrinking.
“For clarity on that, that’s not against either Andretti or GM. Quite the opposite.
“I welcome GM open armed… and I hope to forge a relationship with them should things not work out. They are an incredible entity that I think will make the sport better.”
Mercedes engine customer Williams does not have a power unit supply agreed for 2026.
Asked by Autosport to clarify whether Williams is actively seeking any kind of collaboration with General Motors, Vowles replied: “No… My point is more that an organisation, an OEM like GM, absolutely would be welcome in our sport.
“We would welcome them at this stage. But they’re clearly linked to Andretti - it’s not a question of that and we’re not in talks with them at the moment.”
Additional reporting by Jonathan Noble