New Hampshire’s Bill Gardner, the nation’s longest-serving secretary of state in the country, announced his retirement on Monday after more than 45 years in office.

"In the coming days, I will be stepping down as the secretary of state," Gardner said Monday, adding that he will do so after arrangements have been made for deputy secretary of state David Scanlan to take over. "I have full faith and confidence in him," Gardner added of his deputy.

Gardner, who was first elected in 1976, was a staunch defender of New Hampshire's first-in-the-nation presidential primary. New Hampshire law requires the state’s presidential primary to be held at least seven days ahead of any similar contest, and gives the secretary of state exclusive authority to set the date.

FILE— Then Democratic presidential candidate former Vice President Joe Biden hands the pen to New Hampshire Secretary of State Bill Gardner, left, Nov. 8, 2019, after filing to have his name listed on the New Hampshire primary ballot, in Concord, N.H. (AP Photo/Charles Krupa, File)

The 73-year-old said he's not stepping down due to health issues, but rather because it "comes at probably the smoothest time for it to happen in the cycle of a secretary of state’s four-year cycle." 

He was re-elected in 2020 to a two-year term with no challengers, and experienced virtually no resistance for re-election save for 2018, when he won by just four votes.

“Granite Staters owe a tremendous debt of gratitude to Secretary of State Bill Gardner," Gov. Chris Sununu, a Republican, said in a statement. "For decades, Bill Gardner has fiercely protected New Hampshire’s First in the Nation presidential primary and overseen our elections that are truly a point of pride for our state - always open, fair, accessible, and accurate. We will miss Bill and his vast institutional knowledge of New Hampshire people, politics, and government. Here’s to a well-deserved retirement and best wishes from all the Sununus.”

FILE— New Hampshire Secretary of State Bill Gardner, left, talks with Republican presidential candidate Donald Trump as Trump files his papers to be on the nation's earliest presidential primary ballot, Wednesday, Nov. 4, 2015, at the Statehouse in Concord, N.H. (AP Photo/Jim Cole, File)

Gardner, a Democrat, came under fire from members of his own party for participating in former President Donald Trump’s commission on voter fraud and for backing GOP legislation to tighten voter registration rules.

The Associated Press contributed to this report.