NY- Fernando Ferrer was caught yesterday in a grade-school error – falsely claiming on his campaign Web site he was a product of public schools.

The former Catholic schoolboy quickly pulled the flub from the Internet but not before Mayor Bloomberg’s aides made sure he was taught a campaign lesson he’ll never forget.

“If Freddy Ferrer can’t be trusted to get the facts right about his own schooling, why should voters believe anything he says about education policy?” thundered Bill Cunningham, a senior Bloomberg campaign adviser.

“Only one candidate for mayor this year went to public schools, and that’s Mike Bloomberg,” Cunningham said.

The Ferrer campaign confirmed yesterday that the former Bronx borough president never attended public school; he was enrolled in private parochial schools from kindergarten through 12th grade.

Yet in a Sept. 6 blog entry at www.ferrer2005.com, Ferrer wrote, “I was born in the South Bronx and educated in public schools for most of my education.”

Although the entry was specifically labeled “posted by Fernando Ferrer,” his campaign officials blamed the mistake on an “editing error” by a staffer whom they refused to identify.

Asked about the blog yesterday, Ferrer said he often submits an idea or a draft for the blog “and it will be edited. But the simple fact is … it’s my campaign and it’s my responsibility. So, that’s been corrected.”

This is the second time Ferrer has tripped over the issue of public schools. In an Aug. 16 primary debate, the Democratic candidates were asked whether they would send their children to public schools through high school.

Ferrer responded, “My daughter already did graduate from public schools.”

Ferrer’s daughter, Carlina, attended public school through the eighth grade, but she graduated from Cardinal Spellman High School, the same Bronx parochial school from which Ferrer graduated.

Christy Setzer, a Ferrer spokeswoman, declined to identify the staffer responsible for the editing mistake. Setzer also refused to release the original draft of Ferrer’s blog submission or any evidence to substantiate the campaign’s contention that a staffer, and not Ferrer, made the error. “I guess you’re going to have to believe that,” she said.

Asked to respond to the Bloomberg campaign contention that Ferrer has a history of misleading the public, Ferrer said, “That’s absolute nonsense and everyone knows it. Mike should stop doing that. He should be ashamed of himself.”

By late yesterday, the Ferrer campaign was scrolling through the Bloomberg Web site, issuing a statement calling into question statistics and statements on homelessness and crime. The Bloomberg campaign called the effort “desperate.”

Ferrer’s flub came on the same day that Howard Dean, chairman of the Democratic National Committee, joined Ferrer on the upper West Side to demonstrate national support for Ferrer’s campaign.

Dean called Ferrer the “education candidate,” but when reporters peppered Ferrer with questions about the false blog entry, Dean exclaimed, “What is this obsession with blogs? Does anybody care about education in this city?”

“You started it,” a Ferrer supporter told Dean, referring to his failed presidential campaign.

Meanwhile, the Working Families Party gave Ferrer its endorsement but withheld the party’s ballot line in the Nov. 8 election. The party’s line will remain vacant.