The AFL-CIO's big political gambit in the 1984 presidential election was being put to its first major test in Iowa yesterday, while leaders of the 95 -union federation met in Bal Harbour, Fla., for a week-long midwinter conference.
The federation's policymaking executive council was meeting to deal with an agenda of union matters, including a hospital-union dispute and a petition by airline flight attendants for separation from the Airline Pilots Association into a newly chartered union.
But politics continues to be the council's major interest and one considered by organized labor to be critical this year.
The federation gave an unprecedented early endorsement to Walter F. Mondale for the Democratic presidential nomination during its biennial convention late last year. It did this to solidify labor support for the one candidate it considered to have the best chance for winning the White House in the election this November.
It was a unanimous decision, although many in the federation's leadership ranks had some misgivings about it. They conceded a serious risk to AFL-CIO's political power and influence, should Mr. Mondale fail to win heavy Democratic support during state primaries and caucuses.
The Iowa caucuses were the main thing on the minds of the council's 35 members, as they began what is expected to be a heavy barrage of criticism of the Reagan administration and conservatives in Congress. Council members appeared to be confident of a Mondale victory in Iowa. The question - and political concern - was about how big a victory it might be.
AFL-CIO and its unions, the independent National Educational Association, and other labor-oriented associations have had hundreds of workers busy in Iowa, and an estimated $250,000 in union funds was reported available to the Mondale campaign as it progressed to its climax last night. Other Democratic candidates have sharply criticized this as ''special-interest backing'' for Mr. Mondale.
Unions have also been campaigning strongly in New England in preparation for primaries in New Hampshire Feb. 28 and state caucuses in Maine March 4.
Union political strategists say Mondale would have to ''win big'' in Iowa and do well in New England if he hopes to be a strong candidate going into other areas where his support appears weaker.
Meanwhile, although Reagan administration representatives were not invited to be present during the midwinter conference, the AFL-CIO Building & Construction Trades Department and two affiliates continued to maintain at least limited relations with Labor Secretary Raymond Donovan, who has been ignored generally by organized labor.
Thomas W. Gleason, president of the International Longshoremen's Association (ILA), invited the labor secretary to attend a dinner to be given here tomorrow by a building-and-construction trades council from Long Island, N.Y. The ILA is a council affiliate. On the same day, Mr. Donovan will attend a function arranged by a building trades group from Nassau and Suffolk counties, Long Island.
Robert Georgine, president of the national Building & Construction Trades Department, has invited the labor secretary to address a building trades conference in Washington, D.C., April 2.
However, Frank Drozak, head of AFL-CIO's maritime trades department and of the Seafarer's International union, indicated that maritime unions might withold endorsement of Mondale unless he takes a firm position on maritime issues, including support for rebuilding the United States merchant marine fleet.