The UK government is weighing tariffs on Chinese car imports — not primarily to protect domestic manufacturers, but as the admission price for inclusion in the EU's forthcoming Industrial Accelerator Act, known as "Made in Europe." Brussels has made clear that Britain's current tariff-free treatment of Chinese vehicles creates an asymmetry it cannot tolerate: a backdoor through which Chinese cars and components could flood European markets via Great Britain. Nissan's European chair, Massimiliano Messina, said it plainly — Europe cannot have "a Trojan horse." The numbers explain the urgency. Chinese brands BYD, Leapmotor, and Jaecoo more than tripled their UK market share in 2026, reaching 12% of new car sales. BYD alone sold 68,000 cars through September 2026, nearly doubling its share year-on-year to 5.75% and closing in on BMW's 91,000. Leapmotor sales surged 765%. This isn't a hypothetical threat — it is a market transformation already underway. The structural bind is real. The UK car industry's biggest market for finished products and parts is the EU, underpinning an €80bn trading relationship. If Made in Europe legislation requires continental component sourcing and the UK is excluded for lacking equivalent trade barriers, British-built vehicles face effective exclusion from their primary export market. The risk assessment, according to government sources, has shifted decisively. Imposing tariffs would not be costless. It would likely trigger retaliatory measures from Beijing at a moment when the Starmer government has positioned China as an economic growth partner rather than a security threat. It would also require a lengthy WTO process — the EU's own investigation took 13 months from launch to implementation in October 2024. The UK cannot simply flip a switch. The EU's own framework offers a revealing distinction. Chinese manufacturers operating inside Europe — BYD's Hungarian plant, Chery's potential Sunderland arrangement with Nissan — are treated differently from imports. The policy targets not Chinese ownership but Chinese production outside Europe's regulatory and labor frameworks. This creates a narrow path: the UK could impose tariffs on imports while still welcoming Chinese-owned, UK-based manufacturing that complies with Made in Europe sourcing rules. Mike Hawes of the Society of Motor Manufacturers and Traders captured the industry's position: any tariff consideration needs "robust evidence" and must maintain a rules-based market, but the immediate priority is recognition of the UK as a trusted Made in Europe partner. The subtext is unmistakable — the industry would accept tariffs if that is the price of EU market access. This is fundamentally a sovereignty-versus-market-access question that Brexit was supposed to resolve but instead sharpened. The UK's post-Brexit freedom to set independent trade policy now collides with the economic reality that its auto industry cannot survive without EU integration. The choice is not whether to align with someone — it is whether the alignment partner is Brussels or Beijing.