The 30-year-old Massachusetts mayor running to unseat House Ways and Means Chairman Richard Neal says he's frustrated with how little progress has been made in obtaining President Donald Trump's tax returns — and he's betting primary voters agree.

Alex Morse, the mayor of Holyoke, said Neal, the only Democrat in Congress with the power to seek the president's returns, lacks the "urgency" his constituents in Massachusetts's First District demand.

"I think his action is emblematic of a kind of leader, or lack thereof, that's he's been over the last 30 years," Morse told NBC News in a recent interview, noting that he also takes issue with the 16-term incumbent's refusal to sign on to the Green New Deal or support the House beginning impeachment proceedings.

Morse, Holyoke's mayor since 2011, announced his intent to challenge Neal on Monday.

Neal, a moderate, has come under increasingly sharp criticism from some portions of the left for both not moving quickly enough to obtain the president's federal returns, and so far declining to make use of a newly passed law that would afford his committee access to the president's state filings.

Alex B. Morse, mayor of Holyoke, Massachusetts, on Sept. 29, 2018. Frederick J Gore / The Republican via AP file

"I know people here in western Massachusetts, and people around the country, are frustrated with the way in which he's handled this issue from day one," Morse said. "I mean, Democrats took back the House, and it took [months] to put a letter together. I know it doesn't take us that long to put letters together at City Hall when we have to look at legal issues."

"So, when you look at the timing here, we're now very unlikely to see any result before the 2020 election, because Congressman Neal dragged his feet," Morse added. "We also have people in New York that have worked tirelessly to give the American people access to his New York state tax returns."

That New York legislation, signed into law this month, allows for Neal to make a request for the president's state tax returns should he be stonewalled by the Treasury Department. While many of his fellow chairmen ramped up oversight inquiries soon after the new Congress was seated in January, Neal waited before requesting the president's federal returns. After the Treasury Department refused to furnish them, Neal took months before suing the Treasury and the IRS for the documents.

Neal said last month he wouldn't use the New York law to obtain the state returns because he feels it could harm his legal efforts to receive Trump's federal information. Earlier this week, Trump sued in federal court to keep Neal from being able to use the New York law.

A low-profile member for much of his tenure in office, Neal is no stranger to a left-wing primary challenge. He bested a primary opponent last year, winning more than 70 percent of the vote.

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"We are fortunate to live in a country where everyone can have his or her voice heard by running for office, and that's why Congressman Neal will welcome anyone into this race," Peter Panos, a Neal campaign spokesman, said in a statement. "Richie has been a champion for working families in Western Massachusetts and has fought tirelessly to ensure that the people of our region are not forgotten and receive our fair share."

Rep. Richard Neal, then the ranking member of the House Ways and Means Committee, speaks at a hearing on April 12, 2018. Jose Luis Magana / AP file

Whereas Morse hopes to follow in the footsteps of Reps. Alexandria Ocasio-Cortez, D-N.Y., and Ayanna Pressley, D-Mass., who unseated Democratic incumbents in primaries last year, a source close to the Neal campaign said the congressman, a frequent presence in his large western Massachusetts district, is not about to face the same fate as their opponents.

On Neal's efforts to obtain Trump's taxes, this person said the chairman has "really done everything he could" to obtain them, working "meticulously" with House counsel to lay out the case.

"It's unfortunate that there are folks who aren't living what he's living, making statements and comments and Monday morning quarterbacking the situation," the source said.

On Thursday, Neal's committee released letters that showed the IRS turned over former President Richard Nixon's tax returns the same day a congressional committee requested them in 1973, piercing one of the Trump administration's arguments against furnishing them — that the request is "unprecedented."

Still, Morse believes that left-wing energy that propelled others into office will boost him, too.

"There's something happening in this country," he said. "We, particularly as progressives and young people, are watching what's happening to our democracy right before our eyes."