Lappin, who represents the East Side, is expected to face a crowded field, including Upper Manhattan City Councilman Robert Jackson, former Community Board 1 Chairwoman Julie Menin and Upper West Side City Councilwoman Gale Brewer, in a contentious battle to replace current Borough President Scott Stringer, who is running for comptroller.
Lappin, who grew up in the city and currently chairs the council's Aging Committee, had previously suggested she might run for public advocate, but she made her intentions clear in a January email to supporters announcing she had raised more than $600,000 for a run “for borough-wide office in Manhattan.”
Lappin had $430,000 on-hand as on July.
Menin, who formally launched her bid earlier this month, got an early start on fundraising, and has already raked in nearly $1 million — as much as she is allowed to spend in the Democratic primary when combined with matching funds.
Jackson, who has argued that he holds the advantage as the only minority candidate in the race, got off to a later start and currently has just under $80,000 in the bank.
He'll be holding a high-profile birthday fundraiser next Monday with guests including former Mayor David Dinkins, Rep. Charlie Rangel and City Councilwoman Inez Dickens, according to an invitation for the event.
Brewer, who can not run for reelection for her current council seat because of term limits, has yet to formally announce a borough president run.