Abercrombie said Monday she should leave Congress and allow the state to schedule a special election to fill her seat. She has already said she won't try for re-election next year to focus on the campaign.
The former governor said Gabbard has been absent from some of her duties and her district has lacked proper representation since she announced her White House bid.
"To essentially deprive half the state of Hawaii of representation in that sense is unacceptable," Abercrombie said. "We only have four members in the [congressional] delegation, and just having three there for all intents and purposes does not handle it."
Though Abercrombie is co-chair of State Sen. Kai Kahele's campaign for Gabbard's seat, he said he speaks as a former representative of Hawaii's 1st District who gave up his seat to run for governor.
"Trying to do my job in Washington and run for office, another office, in Hawaii was just too difficult. I couldn't do it," he said. "I had hoped maybe I could do it, and it became obvious that I couldn't. So I resigned my seat."
Abercrombie said Gabbard has rented a home in New Hampshire for the early primary, and he was disappointed she missed most House votes in recent months. She was the only member of either party in the House to vote "present" on both articles of impeachment against President Donald Trump.
"When she just showed up and voted 'present,' I thought - - wait a minute -- that's a step too far," he said.
A spokesman said Gabbard is working hard for her district.
"Just this session, she has secured major legislative wins for Hawaii," the spokesperson said.
"Her pursuit of the highest office in the land has not compromised her."
A special election would be held to succeed Gabbard if she left before her term expires. But that candidate would have to run next November to keep it.