The White House is hotly disputing Republican claims that President Obama’s health care law amounts to a tax on the American people.

Under the law’s individual mandate, everyone must buy health insurance or otherwise face a penalty. Republicans, emboldened by the Supreme Court’s decision to uphold the constitutionality of the mandate on the grounds that the penalty qualifies as a tax, are now attacking the law as  a massive tax increase.

White House spokesman Jay Carney repeatedly refuted Republicans’ argument   to reporters aboard Air Force One on Friday.

“They’re not telling the truth,” Carney said of Republicans. He argued that the penalty is not a tax because people  have a choice to either pay it or buy health insurance, whereas people don’t have a choice when it comes to paying their taxes.

“This is not — you can call it what you want, but it is affecting 1 percent of the population, because most people either have health insurance or will do the responsible thing, and if they can afford health insurance they will purchase it,” Carney said. “I would also not e— it is important to remember this — that the penalty … is modeled exactly on the penalty that exists in the health care reform that was promoted and signed into law by Gov. Romney in Massachusetts.”