Third time won’t be the charm: U.S. Rep. Stephen Lynch finally found a special election he didn’t think he could win.

Citing an "insurmountable" time frame for putting together a statewide organization, Lynch (D-South Boston) on Tuesday took his name out of consideration for a run to succeed the late U.S. Sen. Edward Kennedy.

"After thorough consideration I have decided that I will not be a candidate for the special U.S. Senate race to succeed Edward M. Kennedy," Lynch, a former structural ironworker and labor and employment attorney, said in a statement. "The challenge of putting together the resources and organization necessary to wage a competitive statewide campaign in less than 90 days is insurmountable."

"Running statewide is a daunting task," said state Rep. Marty Walsh, a Savin Hill Democrat and a top Lynch supporter. "It’s hard to put an organization together. You’re talking about thousands of calls you have to make. Some of the candidates were up and running earlier than we thought [they would be]."

Attorney General Martha Coakley, who has been maneuvering to run for more than a year, was the first to declare her candidacy. Congressman Michael Capuano (D-Somerville), who shares representation of Dorchester with Lynch, is mulling a run, as is City Year founder Alan Khazei. On the Republican side, state Sen. Scott Brown of Wrentham and Selectman Robert Burr of Canton have declared their candidacies.

Lynch "just didn’t have labor," said one local political operative, unaffiliated with any of the campaigns.

Coakley has drawn a steady stream of support from labor unions, including the Teamsters Union, and local elected officials. Others have pointed to the lukewarm reception Lynch received at a Labor Day health care rally on Boston Common last week as indicative of what he might have faced in a Democratic primary, thanks to his tepid reception to the idea of a government option in health care reform.

Lynch won his present seat in a 2001 special Congressional election, held on Sept. 11, the same day as the terrorist attacks, after the death of Congressman Joseph Moakley. He was a state senator at the time, winning that seat in a special election after then-state Senate President William Bulger stepped down. His streak caused one local elected official, speaking to the Reporter, to call Lynch the "king of special elections."