An independent government report on President Donald Trump’s new North American trade deal estimates it will lead to higher car prices for U.S. consumers and a decline in auto sales even as it has a modest positive impact on the broader economy, undercutting one of the White House’s key sales pitches for the agreement.

In its assessment of the new U.S.-Mexico-Canada Agreement, the International Trade Commission on Thursday found it would have a modest beneficial impact on the American economy, adding 0.35 percent, or $68 billion, to U.S. gross domestic product in the sixth year after it took effect.

The report offered a much more skeptical view of tough new auto production rules, saying that while they would add 28,000 jobs in the auto sector they would actually lead to a fall in vehicle assembly jobs due to higher production costs that would be a drag on U.S. manufacturing more broadly.

The ITC analysis points to a debate over one of the Trump administration’s main argument for USMCA as it seeks lawmakers’ approval in the months to come: That it will lead to a surge in investment and jobs in an auto sector that has become one of the main drivers of the rising trade deficit with Mexico over the past 25 years.

White House pushback

In a separate analysis released Thursday, administration trade officials said the USMCA would lead to $34 billion in new auto investment in its first five years and 73,000 new jobs.

Kevin Hassett, the chairman of Trump’s Council of Economic Advisers, also raised questions about the ITC’s analysis of the auto sector. The CEA’s own estimate for the broader impact of the USMCA was that it would add $100 billion annually to the U.S. economy once it was fully implemented.

“If we really do get $100 billion more GDP, it is hard to imagine that auto sales will go down,” he said in an interview. “That’s a very big positive to GDP.”

The ITC’s congressionally-mandated report on the likely economic impact found that the strict new auto rules in the USMCA would lead to higher prices for cars in the U.S., reduced consumer choices, the sale of 140,000 fewer vehicles, and a modest decline in auto assembly jobs.

The 1,500 jobs lost in vehicle production, the ITC said, would be offset by a gain of almost 30,000 jobs in parts production thanks in part to increased manufacturing of engines and transmissions in the U.S.

U.S. vehicle prices would also increase from 0.4 percent for pickup trucks to 1.6 percent for small cars.

The ITC also found the increased cost of producing cars in the U.S. resulting from the USMCA may have a broader negative impact by drawing “resources away from other manufacturing sectors and the rest of the U.S. economy, driving up production costs for other sectors.” The result, ITC economists wrote, would be reduced U.S. exports, real incomes and employment in the overall economy.