At their last major debate before next week’s primary election, Vermont’s Democratic gubernatorial candidates assailed one another Thursday over how they — and others — have funded their campaigns.

The Vermont Public Radio debate, broadcast live from Montpelier, came as a flood of outside money inundated the state’s small-dollar political system. Within 24 hours, two super PACs appeared out of nowhere to finance television advertisements for Democrat Sue Minter and Republican Bruce Lisman. In the same period, Silicon Valley venture capitalist Reid Hoffman personally financed a raft of ads for Democrat Matt Dunne.

A third Democrat in the race, former state senator and ambassador Peter Galbraith, used the debate to accuse his primary rivals of hypocrisy for benefiting from the outside cash. Both Minter and Dunne, Galbraith noted, had “made a great show” of refusing corporate campaign donations earlier this year.

“You even ran ads about how you were the first candidate to do it,” he told Dunne. “Now we learn Sue has a super PAC and, today, Reid Hoffman, one of your early campaign contributors and a friend, has just announced he’s spending $220,000 in the last three days of this election.”

Galbraith, a longtime proponent of campaign finance reform, suggested that Dunne had illegally coordinated with Hoffman and called on both of his opponents to denounce their respective benefactors.

“You know, Peter, it came as a surprise to us,” Dunne said of the Californian’s ad buy. “Like everyone else, I didn’t know it was coming. But I’m not surprised that it actually came after the biggest lobbying firm in Montpelier created a super PAC to put money behind an ad that is dishonest about my commitment to clean energy.”

Dunne was referring to Vermonters for Strong Leadership, a super PAC that bought at least $120,000 worth of television advertising this week in support of Minter’s campaign. Funded by EMILY’s List and five wealthy Vermonters, the organization is run by retired KSE Partners lobbyist Bob Sherman. Contrary to Dunne’s assertion, the super PAC is not directly affiliated with Sherman’s former lobbying firm.

Galbraith — a multimillionaire who has largely self-funded his own campaign — disputed Dunne’s assertion that Hoffman’s ad buy was truly independent.

“If you believe that somebody plopped $220,000 in the last three days of the election and it was a total surprise, I’ve got some great investment opportunities in a biotech company in Newport you might be interested in,” he said, alluding to the alleged fraud scheme that has rocked the Northeast Kingdom since April. “I absolutely think there was coordination there. This is really skirting the law. And I’m also concerned, Sue, about your super PAC.”

Minter said she was “against super PACs” and believed “the role of big money in politics is undermining our democracy in very serious ways.” But she denied coordinating with Vermonters for Strong Leadership, claiming she first heard of the super PAC when Seven Days contacted her campaign manager late Wednesday for comment.

“Nothing I can do about it,” she said.

“Yes, you can ask them not to do it,” Galbraith responded. “Will you ask them not to do it — right now?”

“We cannot coordinate,” Minter insisted.

“You can ask them right on the air,” Galbraith said. “You can say, ‘Please do not do this.’”

“We can neither ask—” Minter said. “We’re not allowed to coordinate.”

“That’s not coordination. You have a free speech right. You are perfectly entitled to ask them not to do it,” Galbraith said. “I’m going to say here, ‘If anybody is thinking about spending money independently in support of my campaign, do not do so! I will denounce you to the heavens if you try to do that in my campaign, because it’s wrong! It’s not the Vermont way.’ A quarter of a million dollars into a campaign — it just blows the mind!”

“Including the money that you put into your own campaign, Peter?” Dunne interjected. “How much?”

“I put in $200,000, and I can tell you it isn’t special-interest money,” Galbraith said. “It isn’t some big tech executive who might be wanting to do the next Vermont Health Connect exchange. You know, when you put that kind of money in, somebody wants something.”