Kim Guadagno
Lieutenant governor of New Jersey, Kim Guadagno, has received a resignation letter from her husband, Feb. 21, 2017. In this photo, New Jersey Gov. Chris Christie greets Kim Guadagno after being sworn in for his second term as governor in the Patriots Theater at the War Memorial in Trenton, New Jersey Jan. 21, 2014. REUTERS

New Jersey Lt. Gov. Kim Guadagno has received a resignation letter from her husband, Michael Guadagno, a former appeals court judge, reports said Tuesday. The letter was written on Jan. 26 this year. In order to collect his pension, as the law states, Michael was required to notify Kim, his wife and secretary of state, that he'll reach the mandatory retirement age of 70.

"As you are no doubt aware, next month I will reach the age of constitutionally presumed judicial incapacity, and my term as a judge will end as a matter of law," Michael wrote in the letter.

Kim said that she was surprised by her husband's letter, according to the Associated Press.

"It came into the office cold," she said. "Nobody was more surprised than me that it was coming."

The news comes as the United States sees more women politicians. According to latest data, of the 100 Senate seats, 21 are occupied by women. In the 435-member lower house, women hold 83 seats.

In the letter, Michael also wrote that Kim's term as lieutenant governor would end in January next year and that she could look for other "lucrative positions."

"With your term ending in January 2018, and my income substantially reduced, this may be an excellent opportunity for you to consider a career change to a more lucrative position," he wrote.

He also humorously reminded Kim that she need not reply to his letter and instead they could discuss it "over dinner."

Kim will be running in the GOP primary against Republican Gov. Chris Christie, and her husband's letter appears to point at the ongoing campaign to replace Christie, whose term as governor also expires in January next year. Kim, 57, was the first lieutenant governor of New Jersey, following her wins in 2009 and 2013 elections as Christie's running mate. In 2013, Guadagno and Christie defeated challengers Barbara Buono and Milly Silva.

Kim also concurrently serves as the 33rd secretary of state of New Jersey.

"While we are on the subject, I take this opportunity to remind you that you receive no pension for your work as Lieutenant Governor or Secretary of State, even though, to date, you have served as acting Governor for more than five hundred days," he wrote in the letter.

Kim already earns a salary of $141,000 as the lieutenant governor. As per the state constitution, both appellate division judges and the governor collect salaries of $175,000.

Michael's retirement also means that he can campaign for his wife. Since he held the position of a judge in 2009 and 2013 he was unable to campaign for her.