Palm Beach billionaire Jeff Greene filed as a Democratic candidate for governor Monday – with the self-funder rattling an already crowded and little-known field of candidates.

Greene, 63, entered the race with no immediate public statement, and his office said it wasn’t certain one would be forthcoming.

In April, however, Greene told the Palm Beach Post, “If I did get involved, I’d be able to get my message out and spend whatever it would take to get me over the top.”

Candidates can officially file paperwork to run for governor beginning June 18, in a qualifying week that ends June 22.

Greene spent almost $23 million of his own money in 2010, losing the Democratic primary for U.S. Senate to Democratic Congressman Kendrick Meek of Miami, who went on to lose to Republican Marco Rubio in a race that featured then-Gov. Charlie Crist running as a no-party candidate.

Greene drew only 31 percent of the Democratic vote in the primary.

But with four Democrats already dividing up the electorate, Greene’s entry – and cash – could prove significant.

Polls show voters have not rallied overwhelmingly behind any of those in the current field, including former Miami Beach Mayor Philip Levine, ex-U.S. Rep. Gwen Graham, Orlando businessman Chris King and Tallahassee Mayor Andrew Gillum.

Levine, who also is independently wealthy, has already spent almost $8 million, including $4 million of his own money, helping position him as the likely front-runner in a field where surveys show close to half the voters remain undecided.

Greene’s net worth was put at $3.8 billion on the latest Forbes 400 list of the wealthiest people in America — $700 million ahead of President Donald Trump, his Palm Beach neighbor.

Greene’s wealth comes from real estate and investments, but as a candidate in 2010, he was ridiculed for his excessive lifestyle and partying with celebrities.