Sen. Lisa Murkowski is strongly considering mounting a November write-in campaign to keep her seat and could make an announcement as soon as Thursday, according to a source with knowledge of the situation.

Running as a write-in candidate appears to be Murkowski’s last remaining option. The Senate Republican Conference Vice Chairwoman met with Libertarian Party nominee David Haase on Tuesday to discuss taking his spot on the ballot, but according to a party spokesman, even if Haase dropped out, the party’s executive board — which last week voted against allowing Murkowski on the ballot — does not appear amenable to changing its decision.

Should Murkowski pull the trigger on a write-in campaign, GOP sources say she would face opposition from the National Republican Senatorial Committee. The NRSC endorsed Joe Miller immediately after Murkowski conceded the primary, and the GOP committee intends to stick with the Fairbanks attorney and provide him with the full weight of its backing.

A source at the Miller campaign said they expect to receive support from the national Republican committees.

Another source familiar with Murkowski’s deliberations contends that she has definitely decided to remain in the race and challenge Miller and Democrat Scott McAdams in the general election.

Murkowski told the Fairbanks Daily-News Miner on Tuesday that all options remained on the table.

“I’m no quitter,” she said. “I’m weighing all my options and seeing what’s available.”

To run on the Libertarian Party line, the party would need to switch candidates by Sept. 15. However, that deadline does not pertain to write-in candidates, who have until five days before the election to file a letter of intent.

While waging a write-in campaign is a daunting proposition for any candidate, the one source noted that with Murkowski’s strong name identification, fundraising ability and the state’s election laws, she could pull it off.

According to an Alaska Division of Elections spokeswoman, a voter could spell Murkowski’s name wrong and still have the vote count — as long as the intent of the voter can be determined.

Murkowski is traveling to Hoonah, Alaska, on Wednesday to attend the funeral of two police officers who were killed last month. A Murkowski spokesman was unavailable and did not immediately return an e-mail.