Republican officials in a rural Arizona county refused on Monday to certify the results of the 2022 midterm election, despite no evidence of anything wrong with the count from earlier this month.

Some officials who have embraced voter fraud theories held out, defying a state deadline and setting the stage for a legal battle.

The move came amid pressure from prominent Republicans to reject results showing Democrats winning top races, and the county was holding out in the afternoon of a nail-biting day that was the deadline for several counties to confirm results.

In a lawsuit on Monday, the secretary of state, Katie Hobbs, a Democrat who narrowly won the race for governor, asked a judge to order county officials to canvass the election, which she said was an obligation under Arizona law. Lawyers representing a Cochise county voter and a group of retirees filed a similar lawsuit on Monday, the deadline for counties to approve the official tally of votes, known as the canvass.

The two Republican county supervisors delayed the canvass vote until hearing once more about concerns over the certification of ballot tabulators, though election officials have repeatedly said the equipment is properly approved.

The state elections director, Kori Lorick, wrote in a letter last week that Hobbs was required by law to approve the statewide canvass by next week and would have to exclude Cochise county’s votes if they weren’t received in time.

That would threaten to flip the victor in at least two close races, a US House seat and state schools chief, from a Republican to a Democrat.

Hobbs’ lawsuit asks the Cochise county superior court to order officials to certify the results by Thursday. Failing to certify them would undermine the will of the county’s voters “and sow further confusion and doubt about the integrity of Arizona‘s election system”, lawyers for Hobbs wrote.

“The board of supervisors had all of the information they needed to certify this election and failed to uphold their responsibility for Cochise voters,” Sophia Solis, a spokeswoman for Hobbs, said in an email.

Democratic election attorney Marc Elias also pledged, via Twitter, to sue the county.

Elsewhere, Republican supervisors in Mohave county postponed a certification vote until later on Monday after hearing comments from residents angry about problems with ballot printers in Maricopa county.

Officials in Maricopa county, the state’s largest, where the state capital Phoenix is located, said everyone had a chance to vote and all legal ballots were counted.

Election results have largely been certified without issue in jurisdictions across the nation despite tub-thumping by rightwingers during their campaigns who sought to undermine public faith in US democracy. Many of the most extreme candidates lost.

But it has been a rockier road in Arizona, which became a focal point for efforts by Trump and his allies to overturn the 2020 election and push false narratives of fraud, following Joe Biden’s surprise win in the state – a result that was first called by Fox News, another fact that infuriated Trump as he railed against losing the White House.

Arizona was long a GOP stronghold, but this month Democrats won most of the highest-profile races over Trumpist Republicans.

Lake, who lost the governor’s race to Hobbs, and Mark Finchem, the candidate for secretary of state, have refused to acknowledge their midterm election losses, however. They blame Republican election officials in Maricopa county for a problem with some ballot printers.

David Becker, executive director of the nonpartisan Center for Election Innovation and Research, said the officials delaying certification were breeding an illegitimate distrust in elections and disenfranchising voters.

“In the last year, it’s become an unprecedented dereliction of duty for county officials to violate their oaths of office and refuse to certify election results, citing ‘gut feelings’ or alleged problems in [other] jurisdictions,” Becker said.

Navajo, a rural Republican-leaning county, conservative Yavapai county and Coconino, which is staunchly Democratic, voted to certify on Monday.

In Cochise county, GOP supervisors demanded last week that the secretary of state prove vote-counting machines were legally certified before they would approve the election results.

State elections director Kori Lorick has said the machines are properly certified for use in elections. She wrote in a letter last week that the state would sue to force Cochise county supervisors to certify, and if they don’t do so by the deadline for the statewide canvass on 5 December, the county’s votes would be excluded.

That move threatens to flip the victor in at least two close races – a US House seat and state schools chief – from Republican to Democrat.