A new survey shows American business leaders are much more pessimistic about the U.S. economy than they were only a few months ago — a trend that has continued for more than a year and a half.

The survey, released Wednesday by the conservative Business Roundtable (BRT), found that the index of confidence among top CEOs fell sharply in the third quarter of 2019, to 79.2. That’s 3.5 points below the index’s historical average and the lowest it has been since Donald Trump took office. The survey of 138 CEOs was conducted from Aug. 23 to Sept. 9.

An index of 50 would point to the onset of a recession.

Corporate America’s level of optimism has dramatically receded from the levels when President Trump took office,” reports Axios. “Amid heightened trade war uncertainty, CEOs have downgraded expectations for hiring, capital spending and sales growth — potentially exacerbating fears that the record economic expansion could be coming to an end.”

In a statement released with the survey, BRT president Joshua Bolten described what’s happening:

This quarter’s survey shows American businesses now have their foot poised above the brake, and they’re tapping the brake periodically,” he wrote. “Uncertainty is preventing the full potential of the economy from being unleashed, limiting growth and investment here in the U.S.”

Most observers have focused on Trump’s trade war with the China, but Bolten took a different tack. In his statement, he urged the administration and Congress to make the new North American trade agreement between the U.S., Mexico and Canada the law of the land, saying that would “provide stability and growth to our economy.”

Another poll conducted by the technology data company Morning Consult shortly before the BRT survey found that 46% of American voters think Trump can work out a deal to end the trade war with China, a figure divided on party lines, with 84% of Republicans supporting the president and just 16% of Democrats.