The Democratic gubernatorial primary has been a relatively peaceful affair, with candidates mostly holding their intra-party fire and preferring to criticize Republicans.

Could that be changing?

Andrew Gillum’s campaign released a statement Tuesday hitting Democratic front-runner Gwen Graham for a policy release in which the former congresswoman criticized certain state utility taxes.  

“We welcome Congresswoman Graham to Mayor Gillum’s position,” the statement from Geoff Burgan, Gillum’s communications director, read. “But like Election Year Environmentalist Rick Scott, it feels a lot like an election year conversion — especially since she voted for the Keystone XL Pipeline in Congress.”

Gillum, who has struggled recently to raise money, in March criticized Graham for her 2015 vote in favor of the controversial pipeline. (Former President Barack Obama vetoed the legislation that would have allowed for the pipeline’s construction.)

Gillum’s camp seemed to go somewhat out of its way to criticize Graham for the vote, as Graham’s policy statement did not mention the Keystone pipeline — or anything having to do with crude oil, for that matter. Graham came out against policies that would allow utility companies to tax customers for future nuclear and fracking projects.

“Gwen Graham is taking on outrageous utility taxes levied against Floridians by Tallahassee special interests,” Graham spokesman Matt Harringer said in a statement. “Her bold call to action against the utility industry today, just like her leadership on banning fracking in Florida, show Floridians exactly the kind of change she’ll bring as governor.”

Whether Graham was attempting to curry favor with environmentalists — as Gillum’s camp implied — or Graham was merely articulating a policy position she has long held — as Graham’s campaign argued, the spat could point to the beginning of a contentious primary.