Donald Trump. Win McNamee/Getty Images President Donald Trump's approval rating dipped to a new low on Monday in the latest Rasmussen poll, the survey that is often most favorable to Trump.

Rasmussen found that just 39% of likely US voters approved of the job Trump is doing, while 61% disapproved of the president.

It was the first time Trump dipped below 40% in the Rasmussen presidential tracking poll.

As recently as mid-June, Rasmussen had Trump's approval rating at 50% — far above where other polls found Trump's approval rating to be.

At the time, Trump tweeted: "The new Rasmussen Poll, one of the most accurate in the 2016 Election, just out with a Trump 50% Approval Rating. That's higher than O's #'s!"

Rasmussen interviewed 1,500 likely voters over three days, with a margin of error of 2.5 percentage points.