McLaren Racing CEO Zak Brown sent a formal letter to FIA President Mohammed Ben Sulayem calling for immediate review of Formula 1's common-ownership regulations, specifically targeting teams that share technical resources under separate constructor entries. The correspondence, confirmed by multiple paddock sources, arrived at the FIA's Paris headquarters in late December and names Red Bull Racing's relationship with RB—formerly AlphaTauri—as the structure requiring scrutiny. Brown argues the current framework allows competitive advantages that circumvent the $135 million annual cost cap introduced in 2021.

The letter focuses on two areas: the transfer of intellectual property between sister teams and the rotation of stewards who adjudicate on-track penalties. Red Bull operates both its championship-contending flagship and RB under common ownership by Red Bull GmbH, maintaining separate cost-cap filings but shared wind tunnel time and personnel pipelines. Brown's position is that RB functions as a de facto development subsidiary, testing configurations and driver talent at a fraction of what independent teams spend. McLaren spent approximately $133 million in 2024 under the cap while managing its own junior driver program and simulator resources. The math, Brown's camp notes, does not reconcile when one organization fields twenty race entries per season across two garages.

The timing is operational, not theatrical. The FIA opens its 2026 technical regulations for final comment in February, and Brown wants common-ownership language tightened before those rules lock. His letter also addresses steward consistency, pointing to instances where officials rotated between races involving the same competitors—a dynamic that Brown believes creates conflicts when penalties influence championship outcomes. He stops short of alleging bias but notes the optics problem when stewards rule on teams they previously consulted for or worked alongside in other motorsport categories. The FIA employs a pool of roughly 30 stewards globally, and several have professional histories with multiple teams.

Brown's move arrives as McLaren closes a $1.2 billion valuation following MSP Sports Capital's minority investment and prepares for its 2025 campaign with Lando Norris and Oscar Piastri. The team finished fourth in 2024 constructors' standings, collecting $80 million in prize money, but Brown's public posture suggests McLaren views regulatory equity as critical to closing the gap on Red Bull, which has won three consecutive titles. The letter also serves as positioning ahead of potential ownership changes elsewhere on the grid: Andretti Global remains in discussions with Cadillac backing, and Audi's Sauber takeover completes in 2026. Both entries would enter under single-team structures, and Brown's argument is that allowing multi-team ownership while capping budgets advantages incumbents.

The FIA has not yet responded publicly. Precedent suggests the governing body will convene a teams' meeting during February's pre-season testing in Bahrain, where Brown's proposals will face scrutiny from Christian Horner and the other nine principals. Red Bull has historically defended its structure as compliant with existing regulations, noting that RB operates with independent leadership and commercial contracts. The cost-cap rules permit shared facilities for non-performance functions—hospitality, logistics—but restrict aerodynamic and powertrain collaboration. Brown's contention is that enforcement remains opaque and that the FIA lacks audit resources to verify separation.

The letter does not call for immediate divestiture but requests a working group to draft revised ownership guidelines before the 2026 season. Brown's preferred outcome appears to be clearer firewalls: separate wind tunnel allocations, restricted personnel transfers, and transparent steward disclosures. He has the backing of at least two other teams, according to sources who requested anonymity, though neither Alpine nor Aston Martin has publicly endorsed the letter.

What comes next depends on how the FIA interprets its mandate. The governing body can propose rule changes unilaterally but typically seeks consensus among teams and Formula 1's commercial rights holder, Liberty Media. If Brown's letter gains traction, expect draft language circulated by March and a vote at the April World Motor Sport Council meeting. If it stalls, McLaren's next lever is public pressure—Brown has used media strategy effectively before, including his 2022 comments on budget-cap violations that preceded Red Bull's procedural penalty. The 2026 regulations represent the last major reset before the next Concorde Agreement negotiations in 2027, and Brown is positioning McLaren as the voice for independent teams who believe common ownership creates a two-tier grid.