Sen. Ed Markey defended his decades-long record in Washington while Rep. Seth Moulton argued Democrats need a new generation of leadership during a spirited Democratic primary debate Monday night, where the two repeatedly clashed over foreign policy, financial ethics and the future of the party.

Markey, of Malden, is seeking another term in the U.S. Senate, while Moulton, a Salem native who represents Massachusetts’ 6th Congressional District, is challenging the longtime incumbent in the Democratic primary.

The debate, hosted jointly by Boston 25 and GBH News, featured opening statements, timed responses, and rebuttals on issues ranging from national security to ethics and party leadership.

In his opening statement, Markey said, “There’s a clear choice in this election about who is going to fight for the future of Massachusetts families … I, in each instance, took the right side for Massachusetts, and Congressman Moulton did not.”

Moulton followed, saying he and Markey agree on most issues yet he is “running against a Washington establishment that puts personal power over public service and has been too weak to stand up to the fascist Trump agenda … I believe in a new generation of leadership.”

The two discussed war and national security. Markey sought to link Trump’s war in Iran and soaring energy prices to Moulton’s support for a $1 trillion defense bill, while Moulton, a former Marine, argued that Markey’s 2002 vote for the Iraq invasion sent “thousands of young Americans” like himself into a war that never should have been fought.

Markey said the war in Iran was avoidable, highlighting the need to restore tax breaks for wind and solar energy, which he “was able to put on the books” in the 2022 Inflation Reduction Act.

The 2022 Inflation Reduction Act was the largest climate bill in history that lowers electricity costs, Markey said.

“We have to end the war in Iran. That’s cascading as an energy price onto the kitchen tables of every person in Massachusetts,” Markey said.

Moulton said the first thing the U.S. must do is stop the war in Iran, which will “immediately bring down gas prices.”

He added, “But we also need to have a lot more electricity in Massachusetts, yes, that’s restoring the tax credits for wind and solar — It’s expanding green power all over the state, and it’s a real serious commitment to bringing down electricity prices as part of energy policy. That’s a commitment that I make.”

Wealth and influence also became a topic of discussion. Markey alleged that Moulton benefited from early private investments linked to defense-related companies while serving on the House Armed Services Committee, and Moulton countered by questioning Markey’s telecom record and calling for fuller disclosure of Markey’s family finances.

Markey said that while on the House Armed Services Committee, Moulton was approached by private equity political donors and was given the opportunity to invest in companies such as Divergent, Aura, and WebAI. “At an early stage that’s not open to the public, and then he voted for bloated defense budgets, and out of those investments, he’s made millions. Those companies have made millions. That should be illegal.”

Markey said Moulton should divest from “any of those ill-gotten gains which he has received” due to his membership on the Committee.

Moulton rebutted these claims, saying “these attacks are false; they’re just not true. We have followed every law and ethics rule above and beyond, and every time Senator Markey implies these investments are due to my job and not my wife’s success, that’s not only wrong but it’s sexist.”

Moulton added that both his family and Markey’s have made investments, “but the difference is we have disclosed everything. We’ve disclosed those taxes. But meanwhile, in 1996, you wrote a bill, a telecom deregulation bill, after $400,000 of telecom lobbyist money. That bill made a bunch of telecom billionaires who are paying for your campaign right now. If that’s not pay-to-play, I don’t know what is.”

Moulton said Markey won’t disclose half of his family’s taxes, a precedent started by President Donald Trump, who was the first president in modern history to not disclose his taxes.

Markey also “hasn’t disclosed his health records. Those are common sense things that I think the voters of Massachusetts deserve to see. That’s why I’m transparent. That’s why my family has been completely above board, and that’s the big difference in this race,” Moulton said.

The two also discussed generational change. Moulton urged Democrats to “pass the torch” to younger leaders, voiced support for term limits, and called for an honest discussion about age and fitness to serve

We have term limits — they’re called elections,” Markey said. “Elections are always about the future, and the voters are going to have to decide.”

Even as he defended his own longevity, Markey signaled openness to a shake-up in party leadership on Capitol Hill.

“We need a big debate about new leadership in the Senate, the direction of the Senate,” Markey said, encouraging a debate about new leadership.

Moulton said he supports term limits “because I think too many people in Washington are clinging to power for too long.”

He also highlighted the need to have an “honest discussion about age limits. I mean, we’ve seen what’s happened just in the last few weeks with Senator Graham and Senator McConnell. We cannot afford to lose a vote to Trump and the MAGA Republicans that might result in another conservative Supreme Court justice because a senator missed those votes due to a health reason.”

Moulton said he also supports changing party leadership in the Senate. “The first vote that I take when I get to the United States Senate will not be for Senator (Chuck) Schumer because we need new leadership at the top as well.”