WASHINGTON, Dec. 7 – Sen. Bernie Sanders (I-Vt.), incoming Senate Minority Leader Chuck Schumer (D-N.Y.) and House Minority Leader Nancy Pelosi (D-Calif.) called Wednesday on President-elect Donald Trump to keep his promise to protect Medicare and Social Security.

“Mr. Trump, we are going to hold you accountable,” Sanders said.  “You told the seniors of this country and you told working people you were on their side. Millions of us are going to demand that you keep your promise. We’re going to tell the Republican leadership in the House and the Senate to forget about all their plans to ‘voucherize’ and privatize Social Security, Medicare and Medicaid.”

During his campaign for president, Trump repeatedly promised to protect Medicare. But he nominated Rep. Tom Price (R-Ga.), who has a long history of supporting cuts to Medicare, to run the Department of Health and Human Services.

In March, the president-elect said he would “do everything within my power not to touch Social Security, to leave it the way it is; to make this country rich again.” But the aides in charge of staffing Trump’s Social Security Administration expressed doubts about the viability of the program.

Sanders was joined by grassroots organizations delivering a petition to Senate Majority Leader Mitch McConnell (R-Ky.) and Speaker Paul Ryan (R-Wis.). The petition, which calls on the Republican leaders to follow through on Trump’s campaign promises, garnered more than 1 million signatures.