DALLAS (AP) – Hillary Rodham Clinton’s campaign is launching a new offensive on taxes, saying Bernie Sanders’ health care plan would require middle-class workers to pay higher taxes.

Clinton campaign spokesman Brian Fallon says in a statement that a 2013 proposal by Sanders in the Senate to create a single-payer health care system showed middle-class families would face higher taxes. He says “simple math” shows Sanders would need to tax workers more to pay for his agenda.

Sanders campaign spokesman Michael Briggs says their “Medicare for all” plan would save taxpayers money in the long run because it would eliminate wasteful health spending. He says Clinton supports a system that “props up private insurance companies and pharmaceutical companies” which have given money to her campaign.

Clinton was holding a rally Tuesday in Dallas.