Washington (AFP) - Bernie Sanders has surged to a double-digit lead over his rivals in the race for the Democratic presidential nomination, a new poll published Wednesday has found.

As the self-described democratic socialist rose, moderate former vice president Joe Biden slumped by a whopping 16 point since January's last take of the Washington Post-ABC-News poll.

The Post said Sanders -- at 32 percent support, up from 23 last month -- is climbing on the strength of strong performances in the Iowa caucuses and the New Hampshire primary. Biden stood at 16 percent support in this survey of voter preference.

Third place in the poll went to former New York mayor Mike Bloomberg at 14 percent, followed by progressive Massachusetts Senator Elizabeth Warren at 12 percent.

Pete Buttigieg is in single digits nationally despite narrowly winning in Iowa and finishing a close second in New Hampshire.

The poll was released on the same day of a Democratic debate in which Bloomberg, a New York billionaire accused of buying prominence in the race with staggering spending on campaign ads, will face off against his rivals for the first time.

Bloomberg is expected to come under sharp attack from them for past policies on policing and comments deemed harsh on gender politics and other issues.

The Post said the poll had a margin of error of six percentage points and that it questioned 408 Democratic and Democratic-leaning voters.