U.S. Rep. Stephen Lynch said Monday evening that he would be running for the chairmanship of the House Oversight and Reform Committee, a panel he has sat on for 18 years and one at the center of the House's impeachment inquiry into President Donald Trump.

Lynch, a South Boston Democrat and one of the most conservative members of the state's delegation, said he spoke to colleagues over the weekend before reaching his decision.

The chairmanship is open following the death of Elijah Cummings of Baltimore. U.S. Rep. Carolyn Maloney of New York is the senior Democrat on the committee and the acting chair, and U.S. Rep. Jackie Speier of California has also said she will run.

"It is my hope to continue to the good work of our colleague and friend, Elijah Cummings," Lynch said in a statement. "While we are facing momentous challenges before our Committee, including impeachment, we have many energetic and talented members and staff who are ready and eager to protect and defend the Constitution and the rule of law."

Lynch held out on calling for an impeachment inquiry into the president until September when details were exposed of a phone call between Trump and the Ukrainian president involving the president's push for an investigation of Joe Biden.

Since January, Lynch has chaired the subcommittee on national security. He's one of 23 Democrats on a committee that also includes Boston Congresswoman Ayanna Pressley.

If he were to secure the position, it would mean that representatives from Massachusetts hold the chairmanships of three powerful House committees, including the Ways and Means Committee led by U.S. Rep. Richard Neal of Springfield and the Rules Committee steered by U.S. Rep. Jim McGovern of Worcester.

U.S. Rep. Katherine Clark of Melrose is also the sixth highest ranking Democrat in the House as vice chair of the caucus.