The Boston Public Library , which is preparing to shut down four branches and lay off close to 80 employees to balance its budget, says in a court filing that its former president secretly paid a well-connected lawyer-lobbyist $46,000 for doing no work.

The trustees of the library apparently learned about the payments to lawyer-lobbyist and former state Rep. Maryanne Lewis sometime last fall – nearly three years after they began — and then moved to halt them. In a Sept. 24 letter to Lewis, Ruth Kowal, the library’s director of administration and finance, said the trustees never authorized the payments and were not aware of any services rendered for them.

“The trustees are very concerned with what they have learned concerning these contracts,” Kowal wrote in her letter. “That said, they see little point or advantage to the library in having a protracted dispute with you. They hope that you will treat the contracts, whatever their origins, as now at an end and understand that the library will not voluntarily make any further payments to you.”

But Lewis, who is considering a run as an independent for the congressional seat of US Rep. William Delahunt, refused to walk away. She sued the library trustees, saying she performed the “government relations consulting services” for which she was hired and demanded payment of $32,000 she says she is owed under her current contract, which expires at the end of this year.

The library trustees countersued, seeking the $46,000 Lewis has already been paid and triple damages. In their countersuit, the trustees said former president Bernard Margolis did not have authority to negotiate the contract with Lewis on behalf of the board. The suit claims Lewis’s arrangement with Margolis was not a valid municipal contract and that the trustees were never made aware of it and never approved it. The suit says Lewis “provided no services of value” and notes she never registered as a lobbyist for the library.

Her contract with the BPL says her consulting services include “representing the interests of Boston Public Library as they relate to the municipal, legislative, and executive branches of government.”

Lewis, a former state representative from Dedham who currently lives in Scituate, said in a telephone interview she could not comment while the matter is in litigation. She works as a lawyer and a lobbyist and counts among her lobbying clients the Massachusetts Library Association, a union local affiliated with the Service Employees International Union, Roche Bros. Supermarkets, Titan Outdoors LLC, and the Urban League of Eastern Massachusetts. She reported making $367,400 in lobbying fees last year.

Jeffrey Rudman, chairman of the library trustees, declined comment on the litigation, as did two other trustees.

Margolis, who was ousted as library president in 2007 and later replaced by Amy Ryan, could not be reached for comment. He is reportedly very ill.

Margolis’s departure from the library after 10 years of service followed a nasty split with Mayor Thomas Menino. In an interview with The Boston Globe following his ouster, he accused the mayor and his aides of interfering with library operations, including, according to The Globe, directing him “to hire certain people, ostensibly for political favors.”

Dot Joyce, the mayor’s spokeswoman, referred questions to the Boston Public Library, where spokeswoman Gina Perille declined comment.