Republican Martha McSally, left, and Democat Kyrsten Sinema, who are vying for a Senate seat in Arizona, prepare to debate in Phoenix on Oct. 15. (Rick D'Elia/EPA-EFE/Shutterstock)

Two former aides to the late senator John McCain (R-Ariz.) are publicly criticizing the Republican Party for seeking to cast doubt on the results of the Senate race in Arizona, where Democrat Kyrsten Sinema is narrowly edging out Republican Martha McSally.

The tweets by Mark Salter on Saturday and John Weaver on Sunday come amid ramped-up scrutiny of the race, in which Sinema leads by a little more than one percentage point.

Seventy-five percent of Arizona’s electorate votes by mail, meaning that counting ballots can typically take weeks as officials match voters’ signatures on their ballots with those on their registration forms. Arizona Secretary of State Michele Reagan (R) explained the process in a statement Thursday and said that “everybody is working diligently to tabulate all of the election results in a manner that Arizonans can be proud of and, most importantly, trust the results.”

Yet Republicans at the national level have struck a different note. First, President Trump suggested without evidence in a Friday tweet that there may be “electoral corruption” in the state, raising the prospect of a new election and claiming, “In Arizona, SIGNATURES DON’T MATCH.”

Then, on Saturday, the National Republican Senatorial Committee sent an email to reporters that claimed that the Senate race results were rigged.

“If you thought the Arizona Democrats’ voter suppression tactics weren’t shady enough, now look at the questionable Maricopa County election official who has been using his position to cook the books for Kyrsten Sinema,” the email read.

Salter, McCain’s longtime aide and writing partner, voiced his disapproval of the party’s tactics in a tweet Saturday.

“Stop doing this, NRSC,” he said. “McSally is losing fair and square, and she’s underperforming in more than Maricopa. The race is almost certainly lost and nothing will change that. All this does is poison our politics more. Despicable.”

On Sunday, Weaver, a longtime Republican operative and adviser to the campaigns of McCain and Ohio Gov. John Kasich, followed suit with a tweet Sunday accusing the Senate GOP campaign arm and its chairman, Sen. Cory Gardner (Colo.), of inflicting damage on the electoral process.

“I ran @SenJohnMcCain political world for 10 years & can tell you what is going on in AZ is above board & by the rules,” Weaver said. “The @NRSC & @SenCoryGardner are not only spreading lies & nutty theories, but undermining democracy. @RepMcSally lost this race when she became Trump clone.”

Asked about the dust-up during an appearance on NBC’s “Meet the Press,” Gardner defended the NRSC’s message, although he said that he was not familiar with the “cook the books” email.

“What I do think is important, and it’s not the first time that somebody’s been accused of cooking the books or rigging the outcome of an election,” he said. “I think that’s the last two years have been about Democrats trying to go after President Trump on that as well.”

He added that the committee’s focus is on “making sure that the votes are counted, and the votes are counted fairly.”