ANCHORAGE, Alaska (CNN) -- Alaskan lawmakers investigating Gov. Sarah Palin's firing of her public safety commissioner defended their probe to the state Supreme Court on Tuesday, three days before the deadline for their report.
Palin's Republican allies have asked the court to shut down the legislators' probe, and the justices are scheduled to hear arguments on the issue Wednesday. In a brief filed Tuesday afternoon, lawmakers allege the shutdown request is meant entirely "to avoid a negative impact on the fortunes of one political party."
Palin became the Republican nominee for vice president in August. Shortly afterward, five GOP lawmakers sued to block the probe into her July dismissal of former Public Safety Commissioner Walt Monegan.
Palin's allies have argued that the legislative investigation is a Democratic-led witch hunt and that the state Personnel Board should instead lead the inquiry.
A judge in Anchorage dismissed their suit last week and upheld the legislators' subpoenas for members of Palin's administration, ruling that the Legislature could manage its own investigation.
Palin's allies appealed, which is why the state Supreme Court is hearing the case.
"Completing the investigation and the resulting report in October serves no other purpose than the illegitimate one of trying to deliver an 'October surprise' that will affect the outcome of the national presidential election," the lawyers for Palin's allies wrote.
But the probe's leaders say the record shows Republicans in the Legislature have supported every step the probe has taken.
"What it shows is Alaska's legislators acting with thoughtfulness, collegiality and respect for each other as well as due attention to the rules of their coequal institution," their brief states.
Though the probe has had the support of key Republicans in the Legislature, the GOP members who sued accuse two Democrats -- state Sens. Kim Elton, the chairman of the Legislative Council, and Hollis French, the Judiciary Committee chairman overseeing the probe -- of trying to damage the Republican ticket.
French in particular has been criticized for a September 2 interview with ABC News in which he warned that the probe could result in an "October surprise" for the presidential campaign of Republican Sen. John McCain.
Palin says she fired Monegan in July after months of disagreements over state budgets. But Monegan has said he believes he was fired because he resisted pressure to fire the governor's ex-brother-in-law, State Trooper Mike Wooten.
Palin, who has called Wooten a "rogue trooper" who had threatened her family during his divorce from her sister, has denied any wrongdoing. She said Monegan continued to lobby lawmakers for projects she opposed.
The bipartisan Legislative Council unanimously commissioned the investigation in July, setting an original deadline of October 31 for its completion.
Palin initially pledged to cooperate with the probe. But after she became McCain's running mate, the campaign said Palin would cooperate with the Personnel Board but not the legislative probe, which the campaign has described as being "tainted" by partisan politics.
Since Sunday, seven members of Palin's administration and her husband, Todd, have agreed to give statements to investigators, reversing their earlier refusals to comply with subpoenas. Todd Palin is scheduled to submit written answers to questions through his attorney on Wednesday.
Lawmakers leading the investigation have said Stephen Branchflower, the former Anchorage prosecutor hired to conduct the inquiry, is still scheduled to deliver his report at a public meeting of the Legislative Council on Friday.
The state Personnel Board has hired its own investigator, and both Sarah and Todd Palin are likely to take questions from him on the third week of October, campaign aides said Monday. The three-member panel is appointed by the governor, though its current members were initially appointed by Palin's predecessor.