WASHINGTON — U.S. Rep. Ed Perlmutter plans to announce Tuesday that he will end his run for Colorado governor just three months after the Arvada Democrat began it, according to three sources close to the campaign.

The sixth-term lawmaker also won’t seek re-election in Colorado’s 7th Congressional District; a move likely to bring a sigh of relief to the three Democratic state lawmakers who already have declared for his left-leaning seat, which includes the Denver suburbs of Thornton and Lakewood.

Perlmutter’s campaign did not provide a reason for his exit — telling reporters in a vague statement only that he planned to hold a news conference Tuesday “regarding the gubernatorial race.”

The announcement will be in Golden, where Perlmutter first launched his governor’s campaign in April with the goal of “building an even stronger economy and a more secure middle class with good-paying jobs, affordable higher education and a secure retirement.”

Perlmutter’s surprise decision comes at a time of major upheaval in the 2018 race to replace outgoing Democratic Gov. John Hickenlooper. It’s also being made public just days before gubernatorial candidates are required to file their fundraising hauls for the past three months — often a significant sign of a campaign’s viability.

Top-tier candidates in the Democratic and Republican parties have thrown their hats in the ring. Notable is the recent entry of Democratic U.S. Rep. Jared Polis of Boulder, a longtime Perlmutter colleague in Congress.

Polis, a multimillionaire lawmaker, has the means to invest heavily in his own campaign. That advantage is compounded by Colorado’s strict limits on fundraising — which are far below federal caps — and the reality that Perlmutter would have to compete for a limited pool of primary donors with other Democratic candidates, such as former state Treasurer Cary Kennedy and former state Sen. Mike Johnston.

Another potential factor in Perlmutter’s decision is the possible entry of Lt. Gov. Donna Lynne, which would add another high-powered Democratic competitor.

Whichever candidate emerges from the Democratic primary then would have to face a Republican opponent in a contest that is all but certain to draw national money and attention.

What happens next for Perlmutter is an open question, as the Colorado native has been a staple of state politics. He served in Colorado’s Senate for several years before joining Congress in 2007.

In the House, Perlmutter has been an advocate for NASA, and he played a role in helping to build a new VA hospital in Aurora. The project, which remains unfinished, has been beset with problems and Perlmutter later would criticize the U.S. Department of Veterans Affairs for its mismanagement.

More recently Perlmutter has taken steps to appeal to the Democratic base, and he was one of several lawmakers who briefly considered a formal challenge to the 2016 victory of President Donald Trump. Perlmutter also backed a dark-horse challenger to Nancy Pelosi as the top Democrat in the House.

But sources close to his campaign confirmed he would not seek re-election in the House. That race already has attracted candidates such as Democratic state Sens. Andy Kerr and Dominick Moreno and state Rep. Brittany Pettersen.

“Ed Perlmutter has been a friend, a mentor and a hardworking public servant for the people of Adams and Jefferson counties,” Kerr said. “I wish him nothing but the best in whatever path he chooses next.”