The Connecticut Democrat Elizabeth Esty announced on Monday that she would not seek re-election to Congress, becoming the first national female politician forced out of office because of the #MeToo movement.

Esty, a three-term Democrat from a prosperous district in north-west Connecticut, had faced increasing pressure to step down after it was revealed by the Washington Post that she had kept a former top aide, John Baker, on staff after he made death threats to a former co-worker.

Esty kept Baker on staff for three months after the death threats were reported and even after she received evidence that he had physically assaulted and sexually harassed the former co-worker as well. (Baker disputes that he punched the co-worker.)

He also accompanied the congresswoman to the 2016 Democratic national convention in Philadelphia before leaving with a positive reference from Esty.

In a statement posted on Facebook, Esty said: “I have determined that it is in the best interest of my constituents and my family to end my time in Congress at the end of this year and not seek re-election.”

She went on to express regret for her actions. “Too many women have been harmed by harassment in the workplace,” said Esty. “In the terrible situation in my office, I could have and should have done better. To the survivor, I want to express my strongest apology for letting you down.”

While serving in Congress, Esty was best known as a prominent advocate for gun control measures. Her district includes Newtown, the site of the 2012 mass shooting at Sandy Hook elementary school.

Esty’s decision not to run for re-election opens a competitive seat in the north-east. Hillary Clinton won the district only by a margin of 50% to 46% in 2016.

In a statement, Matt Gorman, the spokesman for the National Republican Campaign Committee (NRCC), said: “Today is a sad day for Connecticut’s 5th District. Elizabeth Esty’s cover-up over her staffer’s domestic violence was as reprehensible as it was morally bankrupt.” He added: “The NRCC is ready to win this competitive seat this fall.”

Esty is the seventh member of Congress to be forced out of office and the first woman. The Democratic senator Al Franken resigned in December after allegations of sexual misconduct. Two Republican members of Congress, Tim Murphy of Pennsylvania and Trent Franks of Arizona, also resigned in 2017 for inappropriate conduct. Three others, the Republicans Blake Farenthold of Texas and Pat Meehan of Pennsylvania and the Democrat Ruben Kilhuen of Nevada, are not seeking re-election after allegations of misconduct.