Rep. Duncan Hunter (R-CA) submitted a letter of resignation to House Speaker Nancy Pelosi (D-CA) and California Gov. Gavin Newsom (D) on Tuesday. He said he would resign his seat effective Jan. 13.

Last month Hunter pleaded guilty to conspiring with his wife Margaret to use more than $150,000 in campaign funds on personal expenses.

The Hunters were indicted in August 2018. Prosecutors detailed thousands of dollars in vacations, flights, school tuition and other everyday costs the couple billed to Hunter’s re-election effort. The congressman initially blamed his wife for any violations. A few months later, she pleaded guilty and cooperated with prosecutors, who in June introduced evidence that Duncan Hunter used campaign funds on extramarital affairs.

Hunter didn’t say in Tuesday’s letter why he’d waited more than a month after pleading guilty to formally resign. Tuesday was the House of Representatives’ first day in session after the holidays.

The Associated Press noted last week that congressional paychecks are distributed on the first day of every month. A spokesperson for the congressman, deputy chief of staff Mike Harrison, didn’t say when asked Monday whether Hunter would keep any salary he received after his guilty plea.

Read Hunter’s letters to Pelosi and Newsom below: