(Image Credit: Steven Senne/AP Photo)

ABC News' Matthew Jaffe, Emily Friedman and Elizabeth Hartfield report:

PEWAUKEE, Wis. - When GOP front-runner Mitt Romney and Rep. Paul Ryan, R-Wis., gathered at a sandwich shop in Waukesha today to drum up support for Romney in the Badger State primary, they might have been engaging in "subs-for-votes" election bribery, according to the state's Democratic Party.

The Democratic Party of Wisconsin issued a complaint of bribery hours after the event, holding a news conference in downtown Milwaukee to air its grievances.

"It is a clear violation of Wisconsin election law, cut and dry," the Democrat Party's representative in Wisconsin told ABC News.

The group is filing its complaint with the state Government Accountability Board, which oversees the elections and will handle the complaint going forward.

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Romney and Ryan's event at Cousins Subs, billed by the former's presidential campaign as an "Election Day Lunch," was attended by a solid crowd on the day of the state's primary.

The two politicos stood behind the store's counter, handed out subs to a long line of people in attendance, and urged them to go vote.

"Get out and vote," Romney urged voters in attendance at the sandwich shop. "If we have a good turnout, then I'll become the person who receives the Wisconsin delegates that I need to go on to become the nominee and finally take back the White House."

Poll workers in parts of Wisconsin were urged this year not to accept donuts from candidates, according to the Appleton Post-Crescent, which also reported that the Obama campaign in 2008 could not provide box lunches to election workers in Milwaukee.

The Romney campaign responded to the complaint from Wisconsin Democrats by accusing the president's campaign of worrying more about refreshments than the economy. But it did not directly address whether the subs might have broken the law.

"President Obama and his allies keep wading in to the Republican primary, whether voting for Mitt Romney's opponents or absurdly claiming we can't provide refreshments for volunteers," Romney spokesman Rick Gorka said. "If President Obama focused half his time worrying about the economy as he does obsessing over Mitt Romney, Americans would be a lot better off."

It is illegal to distribute anything worth more than $1 "in order to induce any elector to go to or refrain from going to the polls," according to the Wisconsin state statute.

The subs Romney and Ryan were handing out today, if bought individually from the store, cost more than $1. Sandwiches at Cousins range in price from $4.49 to $5.59.