Philadelphia's soda tax battle has gone full-on presidential.

Following comments former Secretary of State Hillary Clinton made in Philadelphia Wednesday in support of Mayor Kenney's a proposed tax on sugary drinks to universal fund pre-K education, Vermont Sen. Bernie Sanders said Thursday he's against the tax.

"At a time of massive income and wealth inequality, it should be the people on top who see an increase in their taxes, not low-income and working people," Sanders said in a statement.

Sanders, who said he's for pre-K, went on to criticize Clinton for supporting the soda tax.

Mayor Kenney jumped into the fray Friday morning, calling on Sanders to reverse his position.

"I'm disappointed Sen. Sanders would ignore the interests of thousands of low-income - predominately minority children - and side with greedy beverage corporations who have spent millions in advertising for decades to target low income minority communities," Kenney said.

"It is immoral and completely hypocritical for these vested corporate interests to pass this tax on to the very people they have profited from for decades," Kenney said in a statement.

On Thursday, Sanders said: "Frankly, I am very surprised that Secretary Clinton would support this regressive tax after pledging not to raise taxes on anyone making less than $250,000. This proposal clearly violates her pledge. A tax on soda and juice drinks would disproportionately increase taxes on low-income families in Philadelphia."

Kenney's proposal calls for a 3-cents per ounce tax on all non-diet sodas, sweetened teas, sports drinks, sugary juices and other beverages that contain sugar.

Clinton on Wednesday said, "I'm very supportive of the mayor's proposal to tax soda to get universal preschool for kids. I mean, we need universal preschool. And if that's a way to do it, that's how we should do it."