The AFL-CIO’s embattled president, John Sweeney, plans to kick off his reelection campaign this morning in the face of strong pressure from some labor leaders who are upset by what they see as the federation’s lackluster organizing efforts.

The chiefs of about 15 member unions will congregate in the nation’s capital today to announce the launch of the “Sweeney Solidarity Team,” according to a spokeswoman for the American Federation of State, County, and Municipal Employees, Jodi Sakol. Ms. Sakol told The New York Sun that the labor leaders attending this morning’s press conference will also throw their backing behind the re-election bids of Mr. Sweeney’s top two lieutenants: Linda Chavez-Thompson, the federation’s executive vice president, and Richard Trumka, the federation’s secretary-treasurer.

Ms. Sakol could not provide a complete list of labor leaders who will support Mr. Sweeney at today’s press conference, but she said that among the prominent union presidents slated to attend are Gerald McEntee of Afscme, Edwin Hill of the International Brotherhood of Electrical Workers, and Morton Bahr of the Communications Workers of America. Mr. Bahr’s union is hosting the event at its Washington headquarters.

Delegates from the AFL-CIO’s 57 member unions will convene in Chicago next month, and Mr. Sweeney is widely expected to win a fourth term as president. But the convention is likely to be the scene of a bitter battle between Mr. Sweeney’s supporters and the representatives of the Change to Win Coalition, a five-union group created last week in an effort to reverse the decline in organized labor’s membership rolls. Three unions within the newly formed coalition have publicly considered the possibility of leaving Mr. Sweeney’s federation altogether.