Senator Edward J. Markey out-raised his top primary rival, Representative Joseph P. Kennedy III, during the quarter that ended Sept. 30, raking in $1.1 million to his challenger’s $650,000, according to figures released by both campaigns.
The data provide an early but incomplete peek at what’s expected to be an intense contest for cash in the Democratic Senate primary. The two men entered October still closely matched — Markey with $4.4 million in cash on hand, Kennedy with $4.2 million.
The other Democrat vying for the Senate seat, Brookline labor attorney Shannon Liss-Riordan, had $2.8 million on hand after loaning herself a total of $3 million since launching her campaign in May.
Candidates for the House and Senate had to file their third-quarter fund-raising reports, which cover the three-month period ended Sept. 30, with the Federal Election Commission by Tuesday, but not all reports were immediately available.
While the campaigns’ figures show Markey outpacing his opponents, in Kennedy’s case the smaller haul may not represent the Newton Democrat at full fund-raising tilt.
Kennedy didn’t create a Senate fund-raising committee until late August and did not officially declare his candidacy until a week before the Sept. 30 filing deadline.
Once he opened the Senate account, Kennedy pulled in $100,000 a week, according to his campaign, depositing $400,000 in the past month alone.
Kennedy has built a reputation as a powerhouse fund-raiser in his four terms in the House and has an extensive family network to tap as the campaign gets underway. For example, an Oct. 15 “DC Kickoff” fund-raiser for him was organized and will be hosted by numerous former aides to his great-uncle, the late Senator Edward M. Kennedy.
Considering Massachusetts’ reputation as a fund-raising mecca, Markey’s third-quarter haul isn’t eye-popping for an incumbent — though it does represent his strongest quarter so far this cycle, his campaign said.
By contrast, Senator Jeanne Shaheen, a Democrat from New Hampshire — a smaller state — raised $2.27 million in the third quarter for her reelection campaign and went into the final three months of the year with nearly $4.3 million in cash on hand.
Shaheen is not facing a competitive primary; rather, she will face a Republican challenger in a state where President Trump lost only narrowly in 2016.
In Maine, Sara Gideon, a Democrat hoping to unseat Republican Senator Susan Collins, said she raised $3.2 million in the third quarter.
Two other Democrats are running in the primary for the chance to take on Collins, a top 2020 target for national Democrats.
Republicans are determined not to lose the seat, helping Collins amass a gigantic war chest. Her campaign said she had raised $2.1 million and ended last month with $7.1 million.
Meanwhile, the race to step into Kennedy’s congressional seat continues to heat up. Just weeks after Kennedy officially announced he would not run for the seat, so he could challenge Markey, the field to replace him has grown to five candidates, with several more still mulling jumping into the fray.
Alan Khazei, a Brookline resident and cofounder of the City Year national service program, announced some big numbers of his own — including more than a half-million dollars raised in the three weeks since jumping into the race.
Khazei’s campaign said he raised more than $366,000 by the Sept. 30 quarterly deadline and $136,000 after that, for a total of $502,545 as of Monday.
Khazei, 58, who has twice run for Senate, has also signed up 346 volunteers — a number that is still climbing — who’ve committed to knock on doors, make phone calls, or undertake other actions to help his campaign. Calling them the “Khazei Corps,” he said the volunteer numbers reflect the grass-roots-driven campaign he plans to run.
“Democracy has been captured by special interests and elites,” especially in Washington, he said.
“It’s going to take people power to force open the doors of Congress.”
Other Democrats competing in the primary so far are:
■ Newton City Councilor Becky Walker Grossman, 39.
■ Jake Auchincloss, 31, also a Newton city councilor as well as a former Marine Corps captain.
■ Jesse Mermell, 39, of Brookline, a former top Deval Patrick aide.
■ Ihssane Leckey, 34, a self-described democratic socialist from Brookline who was the only one in the race before Kennedy decided to run for the Senate.
None of the other campaigns shared fund-raising numbers when contacted by the Globe.
Grossman, who announced her candidacy Sept. 24, and Leckey were the only other candidates who had made their bids official before the Sept. 30 deadline.
The district cuts a snaking path from Boston’s western suburbs to the South Coast, including the tony enclaves of Brookline and Newton and the former mill city of Fall River.
Candidates use their war chests for everything from paying staffers to buying television and digital advertisements and lawn signs.