Former U.S Rep. Ed Case raised significantly less than U.S. Rep. Mazie Hirono over the past three months in the Democratic primary campaign for U.S. Senate, according to a copy of his campaign finance report.

Case raised about $147,000 from April through June, according to his report, and had about $206,400 in cash on hand. He had raised about $220,400 in total.

Hirono collected more than $281,000 in the last quarter and had about $545,000 in cash on hand, including money transferred from her congressional campaign.

Case told reporters last week that he had raised about $240,000 for his campaign, but acknowledged that his quarterly figure might be “somewhat different” when his campaign-finance report was filed. He did not, however, suggest that the difference would be substantial.

“Among the lessons I take from this is that I should not comment on a fundraising report until the report is completed and public,” Case said Thursday in an email.

Hirono’s campaign said Case had been misleading.

“Especially since he’s already attacking Mazie Hirono out on the campaign trail, it seems like Ed Case should really focus on getting his own story straight first,” Jadine Nielsen, the Hirono campaign’s finance director, wrote in an email. “It’s never a good idea to mislead the people of Hawaii, even if it’s frustrating to Mr. Case that so many people are joining our grassroots campaign because they agree with Mazie’s progressive agenda of protecting Medicare and Social Security, creating jobs, and strengthening Hawaii’s public schools.”

U.S. Rep. Colleen Hanabusa, who is also considering a Senate campaign, raised $228,000 during the last quarter, so Case had the worst fundraising performance over the past three months among the Democratic contenders to replace U.S. Sen. Daniel Akaka, D-Hawaii.

Case and Hirono had told potential donors of the importance of early fundraising since campaign finance reports are scrutinized by the news media and political analysts for signs of campaign vitality.

Case has lost two statewide primary campaigns — to Hirono for governor in 2002 and to Akaka for Senate in 2006 — and has often struggled to raise money.

Neal Milner, a retired University of Hawaii-Manoa political science professor, said the initial hurdle for Case, who appeals to moderates, is to demonstrate fundraising and political support among the traditional Democrats most likely to vote in the primary.

“This is all about showing people that he can raise money and compete in a Democratic primary,” Milner said.