The U.S.’s biggest health insurer sharply criticized the “Medicare for All” proposals being debated by Democrats, saying they would destabilize the nation’s health-care system and disrupt the economy.

UnitedHealth Group Inc., which provides health insurance to almost 50 million people, said the proposal by some liberal Democrats would amount to a “wholesale disruption of American health care.” Contenders for the Democratic presidential nomination, including Senator Bernie Sanders of Vermont, have called for government-run health care as a way of covering more people, calling it a “human right, not a privilege.”

“The options are clear between a government-sponsored or government-run system and the one we have to offer,” UnitedHealth Chief Executive Officer Dave Wichmann said on a conference call Tuesday, after the health insurance giant reported first-quarter earnings that topped analysts’ estimated. Wichmann said the costs of Medicare for All would “surely have a severe impact on the economy and jobs -- all without fundamentally increasing access to care.”

Health insurance stocks have been rattled in the first few months of 2019 as Democratic presidential contenders have emerged to back variations of Medicare for All, and a resurgent liberal wing of the party in the House has brought the issue to the fore in Congress.

While there are many variations of the Medicare for All idea, in general it involves expanding the program that covers older Americans to the rest of the population. Some proposals would have Medicare as an option for people to buy into and compete with private insurers, while others would replace the entire private health-insurance system with Medicare.

“The path forward is to achieve universal coverage and it can be substantially reached through existing public and private platforms,” Wichmann said on the call, saying there should be a health system that “offers the access, choice and coverage protections people seek at a fair cost to the individual and society as a whole.”

UnitedHealth shares were up 2.4 percent to $235.63 at 9:32 a.m. in New York. The company said it 880,000 new customers in the first quarter, compared with a year prior.

This article provided by Bloomberg News.