Former U.S. Senator Scott Brown will not run in the special election for John F. Kerry's vacated senate seat, according to a report Friday by the Associated Press.

The Republican Brown—who lost his seat in November to former Harvard Law School professor Elizabeth Warren—was seen as a favorite to contend for Kerry's seat, which was opened when the 28-year Senate veteran was appointed Secretary of State.

Preliminary polls showed Brown with a comfortable lead over both of his potential Democratic opponents, Fifth District Congressman Edward J. Markey and Eighth District Congressman Stephen F. Lynch, in the special election slated for June 25.

But Brown would have faced some risk had he chosen to run. A loss would have been his second statewide defeat in less than a year, a setback that likely would have ended his political career, according to politically connected experts.

With Brown out of the running, many have speculated that the Massachusetts Republican Party will turn to former Gov. William F. Weld ’66 as its candidate for the seat. Weld could not immediately be reached for comment on Friday.