Fernando Ferrer lost to Mayor Bloomberg three weeks ago, but the financial troubles that plagued his campaign have not ended.

Yesterday the former Democratic mayoral candidate sent an e-mail to supporters soliciting donations to help pay off his campaign’s debt.

In the six-paragraph message, Mr. Ferrer recaps some of his campaign themes, talks about the effectiveness of his efforts, and asks recipients to consider a donation “to help end our campaign in the black.”

The former president of the Bronx reminds supporters that public matching funds are still in effect at a rate of $6 for every $1 privately raised for donations of less than $250. According to the Campaign Finance Board, he is eligible for matching funds until December 31.

A campaign aide to Mr. Ferrer, Kalman Yeger, would not disclose how high the campaign’s debt is running.

Candidates who ran in the latest election are required to file final disclosure statements with the CFB next week.

“We’re going to file in about a week and it will be clear then,” Mr. Yeger said.

Earlier this month, a top adviser to Mr. Ferrer, Luis Miranda, told the New York Post that a preliminary review found that the campaign was $700,000 in the hole.

“We spent more than we had. We have outstanding liabilities that we have to pay,” Mr. Miranda was quoted as saying. The campaign’s outstanding liability was about $17,500 as of the last filing on October 28.

Mr. Ferrer’s fund-raising troubles plagued him throughout a race in which he was trying to compete with a billionaire who was self-financing his campaign. The Democrat had a tough time convincing donors to open their wallets despite Mr. Bloomberg’s high approval ratings.

Mr. Ferrer raised $5.1 million and received $3.9 million in public matching funds. In late October, his campaign took out a $500,000 loan, which it has already repaid.

A CFB spokeswoman, Andrea Lynn, said candidates are not paid post election funds until the board conducts its final audit on their campaign books, which could take a year.

She said it is “not uncommon” for candidates to receive matching funds after an election, but said expenditures must adhere to guidelines.

Political observers predicted it would be challenging for a candidate who has already lost to secure donations.

A professor of public affairs at Baruch College, David Birdsell, said most people are going to be “directing their money to the person they think is most likely to become the next mayor, rather than to retire this particular campaign’s debt.”

He added, “We don’t know how seriously in arrears the campaign might be and that may prod some people to give, but only people who are very close to the campaign and people who identify with Freddy Ferrer.”

The leader of the Liberal Party, Henry Stern, who has been critical of the “excessive” public matching funds, said it was “not unreasonable” for candidates to receive postelection matching money, but only if it is used for legitimate expenses.

He reasoned that it is often difficult to determine what money is coming in and exactly how much money exists during the final days of a campaign.

“I think it’s honorable to try to pay a deficit rather than run away from it,” Mr. Stern said. “But a postpartum payment, which this is, should receive the closest scrutiny.”

He said the bigger issues, the ones that must be reviewed, are the $6-to-$1 match, the fact that the City Council has influence on campaign-finance regulations, and that in the past some candidates have tried to inflate their expenditures to cover patronage campaign jobs.