Americans for Prosperity, the group financed by the billionaire industrialists Charles and David Koch, is going on air to attack Virginia Democratic gubernatorial contender Ralph Northam as part of a multi-million dollar campaign.

A commercial set to air Thursday on networks statewide blasts Northam, the sitting lieutenant governor, for missing board meetings of the Virginia Economic Development Partnership.

The partnership, created by the state legislature in 1995 to boost economic development, has long been criticized for waste and dysfunction. In 2014, while Northam served on its board of directors, the agency approved a $1.4 million state grant to a Chinese firm that promised to open a factory in Appomattox County but never did. The money was never returned to the state.

Levi Russell, a spokesman for Americans for Prosperity, said the ad buy ranges from $1 million to $2 million, and will run for three weeks. He said the commercial is the first round of paid television advertising, but declined to say how much the organization plans to spend through Election Day in November.

Northam faces Republican Ed Gillespie, a longtime GOP party operative who was the keynote speaker at Americans for Prosperity's summit in Richmond in August.

Gillespie's campaign has criticized Northam for missing meetings of various boards and commissions on which the lieutenant governor sits, dubbing him "No Show Northam."

The new Americans for Prosperity ad echoes the same strategy.

It claims Northam's absence from board meetings of the Virginia Economic Development Partnership amounted to a failure of supervision that "let a fake Chinese company with a false address and phony website to take $1.4 million of our money."

This grant was cited in a blistering performance review by the legislature's audit arm, and led to an overhaul of the agency's oversight and board.

At the time of the grant award, Northam was one of 24 board members that oversaw the agency. Board members were not directly involved in grant decisions; grants were recommended by staff and approved by the governor.

Northam's campaign aides said the Democrat had a limited involvement with the grant.

"Relying on misleading facts to manufacture false attacks is a sure sign of a flailing campaign that's hoping for traction," said Ofirah Yheskel, a Northam spokeswoman. "Ed Gillespie, a K Street lobbyist and the architect of dark money in politics, is so desperate that he needs to be bailed out by the Koch brothers."

Virginia's gubernatorial contest is the nation's marquee race this year, and is widely watched by both national parties as a precursor to the 2018 mid-terms and a test of politics in the era of President Trump.

The race has drawn intense interest from outside groups, and Americans for Prosperity is shaping up to be one of the biggest players on the Republican side.

Nationally, the political network led by billionaire Charles Koch plans to spend between $300 million and $400 million next year promoting policies and candidates favoring limited government.

"Our Virginia chapter has a responsibility, and its role is to stick up for taxpayers, so we are not viewing this through a national lens, but viewing this more of as who would be best governor and who would have the best ideas," said Russell.

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Americans for Prosperity's ad buy comes on top of more than $300,000 it has already funded in anti-Northam mailers, door hangers and digital advertising, according to data compiled by the Virginia Public Access Project.

The organization, which has five field offices in Virginia, says its staff and volunteers have already reached tens of thousands of voters by phone and canvassing.

Americans for Prosperity officials say they are opposing Northam because they believe he has a bad record on taxes and reducing regulations.

"We believe Ed Gillespie would be a much better governor than Ralph Northam with the policies he's put forward...the tax cuts proposals he's put forward," said Tim Phillips, president of Americans for Prosperity. "This effort, though, is focused on Ralph Northam and expressly advocating his defeat."

One of the organization's mailers claims Northam voted for the "largest tax increase in Virginia history," an attack line used by the Gillespie campaign to describe a vote that Northam took on a compromise bill about transportation funding that was crafted by then-Gov. Robert F. McDonnell and GOP legislative leaders.

Outside groups have also flocked to support Northam's campaign.

Planned Parenthood's Virginia political affiliates, the Virginia League of Conservation Voters and billionaire climate change activist Tom Steyer's NextGen America have all committed to spend millions to elect Northam and other state Democrats.

According to the most recent filings, Gillespie had more than twice as much campaign cash on hand as Northam.