With Arizona's U.S. Senate race at stake, President Donald Trump raised the prospect of a "new Election" as well as "electoral corruption."

Trump's tweet came as his candidate, Republican hopeful Martha McSally, lagged behind Democratic hopeful Kyrsten Sinema, and as local GOP groups were headed to court over election-related practices in Maricopa County and Pima County, where McSally was at a disadvantage.

"Just out — in Arizona, SIGNATURES DON'T MATCH," Trump wrote on Twitter, just minutes before a court hearing involving the practices in question.

"Electoral corruption — Call for a new Election? We must protect our Democracy!"

UPDATE:Kyrsten Sinema's lead over Martha McSally widens

ROBERTS:Trump, Republicans becoming unhinged over vote counts

That tweet centered on local Republicans' assertions involving the verification of mismatched signatures on early ballots. Maricopa County Recorder Adrian Fontes, a Democrat, has said verifying the signatures in question guarantees that all admissible votes are counted. Fontes has denied the Republican allegation that he has destroyed evidence.

"There are two parts to this issue, the ballot and the envelope," Fontes said Friday in a written statement. "The GOP asked me to sequester both as evidence. Keeping the ballots separate and uncounted is illegal, and I refuse to disenfranchise voters. But, I still have the envelopes. So if they want to sue me for something I understand the Clerk's Office is open until 5 p.m."

Trump did not offer any evidence for his claim of "electoral corruption."

Trump rallied for McSally back in October, hoping to enthuse the GOP base and turn out voters who might have otherwise sat out the election.

Early election-night results put McSally in the lead. But as county election officials began processing early votes received on Election Day and in the days leading up to it, McSally lost her lead.

On Thursday night, Sinema gained the upper hand. As of 2 p.m. Friday, Sinema's lead stood at 8,256 votes. The Secretary of State's Office is scheduled to update results at 5 p.m. Friday and every day until results are final.

Trump addressed Sinema's lead during a press gaggle on Friday.

"But it is interesting — it always seems to go the way of the Democrats," he said. "Now, in Arizona, all of a sudden, out of the wilderness, they find a lot of votes. And she's — the other candidate — is just winning by a hair."

Representatives of Fontes' office, Sinema's campaign and the state Democratic Party declined to comment.

Follow the reporter on Twitter and Facebook. Contact her at yvonne.wingett@arizonarepublic.com.