(CN) - New York City Mayor Bill de Blasio played defense for the Hillary Clinton campaign on Friday afternoon, staunchly rejecting assertions she's in the pocket of the oil and gas industry.
"I've known Hillary Clinton since 1999 and know her as someone who fights for what she believes in," de Blasio said during a briefing with reporters.
"The allegations now being made that's she's somehow beholden to the fossil fuel industry just don't hold water," he said. "This attack is not becoming of Sen. [Bernie] Sanders and I think we should just get back to the issues."
De Blasio's news conference on behalf of the campaign, announced just a half hour before it started, came a day after the Clinton got into a heated exchange with a climate activist on a rope line during a campaign event, and said she was "so sick of the Sanders campaign lying" about donations she's purportedly received from oil and coal companies and their lobbyists.
Eva Resnick-Day, the Greenpeace activist who got in the verbal tussle with Clinton, had asked the Democratic presidential frontrunner "Will you act on your word to reject fossil fuel money in the future in your campaign?"
As captured in a video Greenpeace USA immediately posted on YouTube, Clinton answered Resnick-Day's question in a straight-forward manner. But when the activist followed up by asking if the candidate would also reject money from registered lobbyists, the candidate flared back at her.
"I'm so sick," she said.
"I'm so sick of the Sanders campaign lying about this. I'm sick of it."
On Friday morning, Jeff Weaver, the Vermont senator's campaign manager, issued a statement in which he said "it is disappointing that Secretary Clinton has leveled an accusation that just isn't true."
"It's very clear from research done by Greenpeace that she's not just receiving money from 'individuals' who happen to work in the oil, coal and gas industry," Weaver continued. "Fifty-seven lobbyists from the industry have personally given to her campaign and 11 of those lobbyists have bundled more than $1 million to help put her in the White House.
"If you include money given to super PACs backing Clinton, the fossil fuel industry has given more than $4.5 million in support of Clinton's bid," he said.
"If the Clinton campaign wants to argue that industry lobbyists giving thousands of dollars to her campaign won't affect her decisions if she's elected, that's fine," Weaver added. "But to call us liars for pointing out basic facts about the secretary's fundraising is deeply cynical and very disappointing."
de Blasio said he didn't know exactly how much Clinton has received from those employed by the fossil fuel industry or its lobbyists, but insisted its "hundreds of thousands of dollars" out of the hundreds of millions raised to wage the presidential campaign.
The mayor then changed gears and began talking about critical points in Clinton's public career, including her effort as first lady to get the 1993 healthcare reform package passed.
"She was unyielding and unafraid no matter what [her critics] threw at her and that is the nature of the person," de Blasio said.
"There is no question of her commitment to fighting climate change and any suggestion that she is in anyone's pocket is flat out false and inappropriate," he said.