Hillary Clinton and Donald Trump are tied, 46-46, in a head-to-head matchup among likely voters, according to a national Bloomberg Politics poll released Monday morning.

Since Bloomberg Politics’ August poll, when Clinton led Trump by six points among likely voters, the Democratic nominee dropped four points and Trump gained two points.

When third party candidates were added to the question in the poll released Monday morning, Trump led Clinton by two points, 43-41, among likely voters with Libertarian Gary Johnson at 8 points and Green Party candidate Jill Stein at 4 points. In the August Bloomberg poll, Clinton led Trump by four points in a four-person race among likely voters, 44-40, with Johnson at 9 points and Stein at 4 points.

TPM’s PollTracker Average shows Clinton leading Trump 46.2 to 45.6.

Iowa pollster Ann Selzer conducted the poll for Bloomberg Politics. Selzer surveyed 1,002 likely voters via phone Sept. 21-24 with a margin of error plus or minus 3.1 percentage points.