A recount in a political race in Massachusetts has flipped a state house of representatives election from Republican to Democrat by a single vote.

Democrat Kristin Kassner won against her Republican opponent and five-term incumbent Lenny Mirra earlier this week after a recount that shrunk the candidates’ narrow vote deficit to one. The candidates were all vying for a seat based in the North Shore area, which is a coastal region between Boston and New Hampshire.

Prior to the recount, Mirra led Kassner by 10 votes out of over 23,000 ballots that were cast in that region during the 8 November midterm election.

The 10-vote deficit was within the legal threshold of a recount. On 30 November, Massachusetts secretary of state Bill Galvin ordered hand recounts in a general area where Mirra held a slim advantage.

After officials recounted the votes in question Thursday, the results emerged as 11,763 to 11,762.

Kassner was ahead by the slightest of margins.

In response to that outcome, Mirra said that he will “absolutely” challenge the result, the Boston Globe reports.

“Some [ballots] were filled out in pencil, some were filled out with different colored ink, some had stray marks. Some had a name written in the write-in and then an oval filled out,” the outlet reported him saying.

Meanwhile, Kassner believes that there was no foul-play in the voting process, saying, “I feel the process unfolded like it should. We’ll see what comes when it comes,” the Boston Globe reports.

“We are not suspicious of anything that ever happened. [The recount] was just really just to ensure that, between humans and machines, we really caught every vote that was counted,” Kassner told CBS.

“We thank the tremendous outpouring of people that really got involved and mobilized to go through this process this weekend. It’s really a true test of democracy.”

The new results will now go to governor Charlie Baker and a gubernatorial council for review.

Should the recount go unchanged, Democrats will hold 133 of the 160 house districts come next January – a gain in four more seats compared to what they started the last session with at the beginning of 2021.

In 2020, Massachusetts offered temporary mail-in voting for the first time as a result of pandemic precautions. Earlier this year, lawmakers voted to make permanent mail-in voting and expanded early voting, two measures which Mirra and the rest of the Republican house caucus voted against.

The measures were nevertheless signed into law by Baker this summer.