Congressman Stephen F. Lynch, who has represented the South Boston area since winning office in a 2001 special election, will launch a campaign for the Senate seat vacated Tuesday by new Secretary of State John F. Kerry, the Boston Globe is reporting.

The Globe report cited a source close to Lynch who confirmed that the Congressman has reserved an event space from the Local 7 ironworkers union. The location is fitting for Lynch, a former president of the Local 7 and a candidate who will rely on his ties to organized labor.

Although Congressman Edward J. Markey, of the Fifth District, has polled better than Lynch and has earned many important endorsements, including those of Kerry and Victoria Reggie Kennedy, Lynch's relationship with labor has the potential to be game changing. Steven Tolman, the president of the influential AFL-CIO union, estimated to the Globe last week that Lynch already has the support of about half of the union’s members. According to Tolman, A candidate wins the AFL-CIO endorsement if he or she has the support of two-thirds of the membership.

While the union has not yet decided if it will endorse a Democrat in the primary, which is set to occur six weeks before the June 25 special election, it is certain that Lynch would be the favorite for the nod. "He has an awful lot of long-term commitments and friendships in labor," Tolman told the Globe. "We grew up with him."

Still, it may be an uphill battle for Lynch, whose conservative positions on social issues differentiate him not only from Markey, but also from many Massachusetts liberal democrats.

A member of the House Financial Services committee, Lynch is a graduate of the Wentworth Institute of Technology, the Boston College Law School, and the Kennedy School of Government at Harvard.