Senator Sullivan’s pledge contrasts with the Trump administration’s effort to challenge Alaska’s election certification, if he loses.

Republican Senator Dan S. Sullivan has vowed to accept the election outcome days after the United States Department of Justice filed a lawsuit seeking to decertify the results of the upcoming US Senate race there if the Republican incumbent loses.

“I’m going to accept the election results,” Sullivan, an ally of US President Donald Trump, told CNN on Sunday.

Sullivan’s promise comes just two days before the November 3 midterm election, which will determine control of the US Congress.

He said he was confident of winning, accusing his Democratic opponent Mary Peltola, who is attempting to unseat him, of cheating.

“My opponent and [Senate Minority Leader Chuck] Schumer and his aides are showing complete disrespect for Alaskans, complete disdain in recognising that they couldn’t run on their record, so they had to cheat. And now that that’s been exposed,” he said.

A New York Times report on Wednesday alleged that members of Peltola’s campaign helped recruit a retired teacher named Dan J Sullivan Jr to run for the Senate seat as a spoiler candidate in an attempt to draw votes away from Senator Sullivan.

The report seems to have prompted the Trump administration’s renewed legal push to bar Alaska from certifying its election results, should Senator Sullivan lose.

On Sunday, US District Court Judge Sharon Gleason dismissed the lawsuit, citing it as “infeasible” because many voters had already cast their ballots and the ballots have now been commingled to the point where the identity of each voter cannot be determined.

“More fundamentally, the United States provides no workable plan as to how it proposes to segregate ballots cast for Daniel J. Sullivan on Election Day and then conduct a court-ordered unspecified “investigation” of those ballots in a manner that would preserve voter secrecy,” she wrote.

The second Sullivan is listed on the ballot as Daniel J Sullivan Jr, while the senator is listed as Dan S Sullivan and marked as a Republican incumbent.

Peltola has insisted she had nothing to do with recruiting the other Sullivan and has called attention to it a “distraction” from the main issues facing Alaskans — namely, high prices caused by US-Israel war on Iran. Her campaign has also denied involvement.

Before a rally on Friday, Peltola was asked whether someone on her campaign could have been involved in recruiting the other Sullivan. “I have no idea,” she told KTUU. “I honestly have no idea.”

Senator Sullivan doubted Peltola’s claims.

“There is no way this went on for a year that they weren’t informing her,” Sullivan told the CNN news programme State of the Union. “She got caught lying, and she’s still lying to the Alaskan people, the media, to all of us.”

Alaska’s Senate race is one of seven key toss-ups that will likely decide whether Republicans keep their majority in the US Congress’s upper chamber.

Both candidates have spent the final days campaigning through Alaska’s vast landscape.

On Saturday night, Senator Sullivan handed out candy at a “trunk-or-treat” event at a recreation centre north of Anchorage, where he quipped his costume was “the real Dan Sullivan”.