Former New York City Mayor Michael Bloomberg is now ahead of Senator Kamala Harris in the race for the Democratic Party's nomination for president, according to a new public opinion poll.

The billionaire media mogul, who officially announced his candidacy last week, has 6 per cent support of likely Democratic voters compared to just 2 per cent for Harris, who has been campaigning for months.

The survey, which was taken by Hill-HarrisX, was the first since Bloomberg officially announced his candidacy.

Bloomberg still has a long way to go if he hopes to catch up to the clear frontrunner, former Vice President Joe Biden.

The poll gives Biden a commanding lead with 31 per cent, while Senator Bernie Sanders of Vermont trails him with 15 per cent.

A new poll by The Hill-HarrisX shows former New York City Mayor Michael Bloomberg (left) get more support among likely Democratic voters than Senator Kamala Harris (right)

Bloomberg still has a long way to go to catch frontrunner Joe Biden (center), who gets 31 per cent support in the new poll. Senator Bernie Sanders (right) is in second place with 15 per cent, while Senator Elizabeth Warren (left) is in third place with 10 per cent

Senator Elizabeth Warren, who was once riding high in second place, has seen her stock drop recently in a number of surveys.

The Hill-HarrisX poll puts Warren at 10 per cent support.

South Bend, Indiana, Mayor Pete Buttigieg is at 9 per cent to round out the top five.

While the mayor is the frontrunner in Iowa and New Hampshire, national polls show him trailing significantly behind Biden, Sanders, and Warren.

Harris, entrepreneur Andrew Yang; Senator Amy Klobuchar; former Housing and Urban Development Secretary Julian Castro; and billionaire Tom Steyer are tied at 2 per cent each.

Thirteen per cent of likely Democratic voters are undecided.

Bloomberg, founder and CEO of prominent media company Bloomberg LP and a leading philanthropist, has a financial advantage over his Democratic rivals.

It is on display already as he has spent at least $31million in television ads that will run in states across the country over the next two weeks, a campaign spokesman said.

Ranked by Forbes as the eighth-richest American with an estimated worth of $53.4 billion, Bloomberg joins activist Tom Steyer as the second billionaire to enter the Democratic race and will have the advantage of being able to self-finance his campaign and pour millions of dollars into advertising and hiring staff.

Kelly Mehlenbacher, the former state operations director on Kamala Harris' presidential campaign who quit to join rival Mike Bloomberg's bid for the White House, left behind a stinging resignation letter

The resignation letter submitted by Kelly Mehlenbacher, the former state operations director on Kamala Harris' presidential campaign, says she has 'never seen an organization treat its staff so poorly', after last-minute layoffs

He announced earlier in November a $100 million online ad campaign targeting Trump in four battleground states.

Harris, whose candidacy once appeared promising, has seen her presidential prospects grow dimmer with each week of campaigning.

The senator from California now hopes to get a helping hand from the governor of her home state.

Gavin Newsom will travel to Iowa to campaign for Harris as she tries to rebound amid a critical stretch in the race for the Democratic presidential nomination.

Newsom will visit the first voting state on December 14 and 15 on behalf of Harris, his home-state senator and longtime friend and political ally.

Governor Gavin Newsom, Harris's longtime friend and political ally from her home state of California, will travel to Iowa later this month to give a boost to the senator's floundering campaign

His visit will come as Harris tries to claw back from single digits in the polls and defy the narrative that her campaign is collapsing ahead of the February 3 caucuses.

Harris has staked her campaign on a strong showing in Iowa and recently spent six days over the Thanksgiving holiday campaigning in the state.

But she's still stuck in single digits in most polls, far from the top of the pack that includes Biden and Buttigieg.

In recent weeks her campaign has been beset by a series of negative stories in the media.

The New York Times obtained a scathing resignation letter from a staff member who left in November and now works for Michael Bloomberg´s presidential campaign.

'This is my third presidential campaign and I have never seen an organization treat its staff so poorly,' wrote Kelly Mehlenbacher in the November 11 letter obtained by the New York Times.

The letter came after the once promising campaign announced last-minute layoffs of staff in early November, reports the Times.

Newsom's visit is an example of the public support that Harris still commands from allies in her home state, where her term as senator continues through 2022.