Initially, Meehan had said he would run for a fifth term, but on Thursday he told Speaker of the House Paul Ryan he would not.
Rep. Pat Meehan, R-Penn., has made a decision to not seek re-election this year following reports that he settled a sexual harassment case with a former staffer by using taxpayer funds.
"After consultation with my wife, Carolyn, and with my three sons, and after prayerful reflection, I write to inform you that I will not seek re-election to the United States Congress for the Seventh Congressional District in 2018", Meehan wrote in his retirement letter Thursday, obtained by the Philadelphia Inquirer.
Meehan, 62, helped lead the fight against sexual harassment in his role on the House Ethics Committee until a January 20 New York Times report revealed he settled a sexual harassment claim with an aide more than three decades his junior. "I am confident that the voters of Pennsylvania's 7th District will elect a strong conservative who will represent their values". DiGiorgio called it a "sad ending to what was an otherwise noteworthy career of a dedicated public servant leader".
The report, by the New York Times, was amplified in part because as a member of the House Ethics Committee, Meehan had been helping review sexual harassment claims against several other representatives.
U.S. Rep. Steve Stivers, R-Ohio, the chairman of the National Republican Congressional Committee, thanked Meehan for his dedication, but said, "we must always hold ourselves to the highest possible standard - especially while serving in Congress".
Meehan confirmed the outlines of the Times story, which said the married, 62-year-old expressed his romantic desires to his aide after she began a serious relationship with someone else, and then grew hostile when she did not reciprocate.
She filed a complaint, started working from home and eventually left the job before Meehan's office paid a settlement said to be "in the thousands".
Meehan said he and the woman had worked together for years and that she was a critical hub in his office, a "gatekeeper".
Pennsylvania will now have at least four open seats in its Congressional delegation this November: Meehan in the 7th, Rep. Bill Shuster in the 9th, Rep. Lou Barletta in the 11th, and Rep. Charlie Dent in the 15th.
Democrat Hillary Clinton narrowly won the district in the 2016 presidential election, and winning it likely becomes an even bigger target for Democrats animated by anti-Trump fervor in Philadelphia's suburbs, and more hard for Republicans.