The American Federation of Government Employees has fired a staff attorney who warned AFGE officials in an internal memorandum not to publicize their newly won right to deduct political contributions from D.C. employe paychecks because the arrangement looked like a political deal with Mayor Marion Barry.

Donald M. Haines, legislative attorney for AFGE, was dismissed last Friday, the day The Washington Post published an account of the memorandum.

The dismissal letter from Jane P. McMichael, the union's legislative and political affairs director, accused Haines of failing to "safeguard confidential sensitive legal advice and sensitive and confidential documents." As a result, the letter said, "you have brought disruption, embarrassment and harm to AFGE."

Haines filed a grievance yesterday seeking to overturn the firing, according to Emmett Etheredge, spokesman for Local 2 of the Office and Professional Employees International Union, which represents AFGE's 138 clerical and professional employes.

Haines could not be reached for comment.

The Barry administration agreed in July to allow an AFGE Local 1000, representing 600 city employes, to collect voluntary poltical contributions from employes through payroll checkoffs.

Local 1000 was the first AFGE group in the country to win that right, and the 225,000-member union hopes to implement political checkoffs at locals throughout the country.

AFGE endorsed Barry on May 18, the first time the union has endorsed a mayoral candidate anywhere in the nation.

Haines, in a July memorandum to McMichael, wrote that publicity about the checkoff could hamper AFGE's efforts to win it elsewhere. Because of the political "overtones" in the D.C. case, he said, U.S. agencies might be more likely to raise objections to the checkoff because of the Hatch Act, which prohibits active federal employes from soliciting political contributions from other employes.

Both Barry and AFGE have characterized the checkoff as a voluntary and progressive employe benefit.

AFGE officials declined to discuss Haines' dismissal yesterday. However, union officials have said in the past that they believed an internal split over union leadership has been prompting a stream of criticisms and leaks to the media aimed at damaging union president Kenneth Blaylock, McMichael and other top AFGE officials.