A Northern Virginia congressional hopeful and a Democrat running for the Arlington County Board are calling for a voter referendum on whether the county should launch a streetcar line on Columbia Pike.

Patrick A. Hope, a Virginia state delegate who is seeking the Democratic nomination in the 8th Congressional District race, and Alan Howze, the County Board hopeful, said residents should have a say in whether the 4.5-mile, $310 million streetcar line should be built. Both candidates support the project.

“It’s pretty clear our community is deeply divided over this issue,” said Hope, one of 10 candidates vying for the Democratic nomination to replace retiring Rep. James P. Moran in the district, which includes Arlington, Alexandria, Falls Church and part of Fairfax County. “I think it’s time we have a full public debate and a public referendum . . . and we need to respect whatever the public decides.”

Howze lost a special election in Arlington last month to John Vihstadt, a Republican who ran as an independent and sharply criticized the streetcar project. The two will face off again in November for a full term on the County Board.

“I’m pleased to see Alan Howze now agrees Arlington taxpayers should have a voice regarding the County Board’s misguided proposal to spend hundreds of millions of dollars to install streetcars in Arlington,” Vihstadt said Thursday night.

He called for Arlington to “immediately cease all county spending” related to streetcars, except as required by contracts, and said the referendum should “specify in detail the estimated total cost . . . the detailed financing structure . . . not combined with any other project.”

Howze said it was apparent during this spring’s campaign that Arlington residents are not as supportive of the streetcar as county officials had thought. “Voters clearly didn’t understand why it was the right investment at the right time,” Howze said. “There’s an obligation to educate people and then give them a voice. The issue doesn’t lend itself to a 30-second sound bite, but the billions in economic development that it will bring will help . . . our overcrowded schools.”

Radio talk-show host Mark Levine, who like Hope is competing for the 8th District Democratic nomination, voiced support for a streetcar referendum to the political blog Blue Virginia earlier this week.

The County Board has resisted calls for a referendum, pointing to a decade or more of public discussion about the streetcar project. A consultant’s report commissioned by the board said a streetcar along the Pike would bring in development worth three times what an improved bus system would create.

Board Chairman Jay Fisette (D) said Thursday that he was taken by surprise by Hope’s and Howze’s call for a referendum. “I lived in California for a while when we had 100-plus referenda on the ballot,” Fisette said. “I became very disillusioned about the use of selective referenda on public policy issues.”

Board member Mary Hynes (D) agreed. “It depends on whether you think it’s a good way to make public policy or not,” she said. “I don’t know that I think [a referendum] is the best way to have a robust conversation with the community about anything.”

Fisette emphasized that no money from homeowners’ taxes would go toward building a streetcar line. County officials expect to pay for the streetcar with a combination of federal, state and local funds, with the local money coming from a 12.5-cent surcharge on commercial real estate that can only be used for transportation.

Where the federal money would come from is not clear. Local officials were turned down in April 2013 when they applied for funding from the federal “Small Starts” program. Transportation officials doubted the $250 million price tag that the county had put on the project at that time. Arlington officials are deciding whether to apply for a different federal program.

Fisette and board Vice Chairman J. Walter Tejada (D) noted Thursday that they are starting two months of deliberations over the capital budget, which may include money for schools, community centers, street improvements and other infrastructure. A streetcar referendum could divert attention from those spending needs, Tejada said.

Hope said there are two ways to hold a local referendum, such as including the issue in the county’s transportation bond in November, which the County Board could order. If it chose not to do that, the General Assembly could put an advisory referendum on the November 2015 ballot, he said.

Noting that his legislative district includes parts of Columbia Pike, Hope reiterated his support for “major transportation investments in that corridor that will ease congestion and stimulate job creation and economic development.”

“We need to move forward quickly with those improvements,” Hope said. “I don’t think there’s a clear support, a mandate [for the streetcar] right now. But I think when you explain the economic benefits all around the community, and not just along the Pike, they will be supportive. But we can’t keep doing what the voters don’t want us to do.”