(Bloomberg) -- Senator Bernie Sanders has jumped to the lead in Iowa over Pete Buttigieg and Joe Biden, while support for Elizabeth Warren has slipped, according to a New York Times/Siena poll released on Saturday. The first-in-the-nation Iowa caucuses will be held Feb. 3. Sanders had the support of 25% of likely caucus-goers, up six points since the previous version of the survey in late October.

He’s pulled ahead of Buttigieg, the former South Bend, Indiana, mayor at 18% and former Vice President Biden at 17%. Warren was at 15% and Amy Klobuchar at 8%, days after the two U.S. senators received a joint endorsement from the newspaper. The survey of 1,689 registered voters in Iowa, including 584 Democratic caucus-goers, was conducted Jan. 20-23 and had a margin of error of plus or minus 4.8 percentage points for the Democratic caucus electorate and 2.8 percentage points for registered voters.

COMING UP:

Some of the Democratic candidates will debate again in New Hampshire on Feb. 7.

The first-in-the-nation Iowa caucuses will be held Feb. 3. The New Hampshire primary is Feb. 11. Nevada holds its caucuses on Feb. 22 and South Carolina has a primary on Feb. 29.

CNN will host town halls featuring eight presidential candidates in New Hampshire on Feb. 5 and 6.

(Disclaimer: Michael Bloomberg is also seeking the Democratic presidential nomination. He is the founder and majority owner of Bloomberg LP, the parent company of Bloomberg News.)

To contact the reporter on this story: Ros Krasny in Washington at rkrasny1@bloomberg.net

To contact the editors responsible for this story: Wendy Benjaminson at wbenjaminson@bloomberg.net, Ros Krasny

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