At the National Democratic Club, a watering hole tucked away on a Capitol Hill side street, the talk around dimly lit tables is deficit. Not the nation's billions, but free-spending delinquent members who haven't paid their tabs in months.

The club has decided to take action to embarrass the members into paying. Along with the photographs of former Democratic presidents in the foyer, the club has posted a list of dozens of members, including some prominent names, who have owed for more than 90 days amounts from $100 to more than $1,000. And now it's threatening to build a bigger bulletin board.

"It's essential {posting}, and the club may have to build a new bulletin board if the full 19-page printout of delinquents are to be displayed," wrote newsletter editor Ivan (Red) Swift in the most recent issue of Club Talk. The newsletter notes the club at 30 Ivy St. SE has more than $178,000 in bad debts on the books.

But now the club wants to enforce its policy that delinquent members are barred from the club until they're paid up.

Among the posted names, under those owing from $101 to $250, are Mayor Marion Barry and Del. Walter E. Fauntroy (D-D.C.). Two members of Congress, Sen. Dennis DeConcini (D-Ariz.) and Rep. John Conyers Jr. (D-Mich.), owe $1,001 or more, according to the list.

Fauntroy and spokesmen for DeConcini and Conyers all said the overdue bills were misunderstandings, but Barry's office said yesterday that the mayor thought he had been given a free membership.

"It's a private club and the mayor said he initially was given a free membership," said Press Secretary John C. White. "He thought that since he was the city's No. 1 Democrat that the free membership would continue." Barry has rarely used the club and is reevaluating whether he wants to be a paying member, White said.

Officials said yesterday that the club had been billing Barry's office, but that George Thomas, controller for the mayor's office, has refused to pay the bills because they did not appear to be government related.

Fauntroy said he believed that he wrote a check to cover a $180 dinner.

"I'm pretty sure I took care of that last week," said Fauntroy, who said he would check with the private club that features a restaurant, bar and meeting rooms. Club officials declined to comment on their operations, but the club's August newsletter detailed financial problems.

"Nobody wants to bar a member . . . but the deficit fiscal situation we're in can be eased simply by enforcing the by-laws . . . . The Club's got bills in arrears, too. If you'd seen the delinquent list, you'd know why."

Bob Maynes, press secretary for DeConcini, said the Arizona senator's bill stemmed from a campaign fund-raising dinner sponsored by the National Treasury Employees Union. Pat Smith, a spokesman for the union, confirmed that the union was supposed to have arranged for the bill to be paid by DeConcini's campaign in Arizona.

A Conyers spokesman said the congressman's bill stems from a labor function that will be paid by the union involved. "There's been some problems in communication," said legislative director Julian Epstein. "Lord knows we don't believe in deficits and it will be taken care of shortly."