Mirkarimi pleaded guilty in March to a misdemeanor false imprisonment charge in an allegation of domestic violence against his wife.
He was sentenced to three years' probation and other penalties and was subsequently suspended without pay by Mayor Ed Lee on official misconduct charges.
Mirkarimi is awaiting a hearing on the administrative charges before the city's Ethics Commission, which will then make a recommendation to the Board of Supervisors on whether to uphold the charges and remove him from office.
A representative for the city attorney's office said it received a belated letter from Mirkarimi requesting public financing for his legal defense in the proceedings.
According to the city attorney's office, Mirkarimi's letter that was received on Tuesday was dated May 15, 2012, weeks after Mirkarimi retained attorneys Shepard Kopp and David Waggoner.
In a response to Mirkarimi's request addressed to Kopp and Waggoner, City Attorney Dennis Herrera says "there is simply no legal basis for your client's demand for City funded representation."
Herrera argues that the sections of the City Charter that Mirkarimi cites as justification for his request are not applicable, in part because the City Attorney's client is the city itself, not individual elected officials.
"There is no legal authority supporting your client's demand to have the City fund his personal defense against charges of misconduct, and the City Attorney's Office will not authorize the use of taxpayer funds for this purpose," Herrera wrote.