State Rep. Marty WalshState Rep. Martin Walsh (D-Dorchester) said Monday he won't be running for president of the AFL-CIO. Robert Haynes, who held the post since 1998, said last week he would not be running for reelection in October.

The announcement sparked speculation that Walsh, a longtime labor leader and activist, would be a top candidate for a job that includes representing the interests of 400,000 union members in Massachusetts.

Walsh said he was honored to have been asked to run for the job by several unions, but it wasn't the "right time" for him. "I feel like I could do more good for the labor movement on Beacon Hill as a member of the Legislature," he said.

Walsh is also the secretary-treasurer and general agent of the Boston Building Trades Council and president of Local 223, a construction and general laborers' union.

Asked if he was throwing his support behind a candidate, Walsh said not at this time.

"As far as serving the people of Dorchester, I enjoy it and I want to continue doing it," he added.

Walsh has served in the Thirteenth Suffolk District seat since 1997, when he won a four-way special election.

In the Legislature, he serves as chairman of the House Ethics Committee.

Haynes, in a letter to union members, said he supports Tim Sullivan of OPEIU Local #6 as his successor.