Many Democrats are pushing to include raising the national minimum wage from $7.25 to $15 in President Joe Biden’s $1.9 trillion COVID stimulus package, and the House is set to include it in the legislation it will later send up to the Senate.

However, hiking the minimum wage to $15 is opposed by two Senate Democrats in particular: Senator Joe Manchin (D-WV) and Senator Kyrsten Sinema (D-AZ). Both have ruled out voting for it.

There is a 50-50 split in the Senate between Republicans and the Democratic caucus. Vice President Kamala Harris has the deciding vote in ties, giving Democrats a narrow and fragile majority.

“A $15 minimum wage is not a radical idea,” Sanders tweeted on Sunday. “What’s radical is the fact that millions of Americans are forced to work for starvation wages, while 650 billionaires became over $1 trillion richer during a global pandemic. Yes. We must raise the minimum wage to a living wage.”

The tweet follows comments on Friday when Sanders expressed confidence to reporters about having the bill included in the overall package.

“We’re feeling really good. We think we’ve got a good shot,” Sanders, chairman of the Senate Budget Committee, told reporters at the U.S. Capitol, adding: “We’ve got to raise the minimum wage to a living wage of $15 an hour and that’s what the American people want and that’s what I intend to do.”

“What’s important is whether or not it’s directly related to short-term COVID relief. And if it’s not, then I am not going to support it in this legislation,” Sinema told Politico in an interview published Friday.

“The minimum wage provision is not appropriate for the reconciliation process. It is not a budget item. And it shouldn’t be in there.”

Republican Senators oppose including the minimum wage, arguing it would be too costly to small businesses, many of which have struggled as a result of the pandemic.

The Congressional Budget Office said last week that 900,000 Americans would be lifted out of poverty if the minimum wage was raised to $15.

However, it also estimated that the increase would lead to the loss of 1.4 million jobs and increase the federal budget deficit by $54 billion over the next 10 years.

Under the Democrats’ proposal, the wage increase would be phased in through to 2025.

The minimum wage was last increased in 2009, however many states have higher wages. Pennsylvania’s Democratic Governor Tom Wolf proposed last week raising his state’s minimum wage to $15 by 2027.

A $15 minimum wage has been the goal of Sanders and many other progressive Democrats for a number of years and is backed by the “Fight for $15” movement.

House Budget Committee Chairman John Yarmuth (D-KY) told The Wall Street Journal he would “almost guarantee” that the $15 minimum wage would end up as a standalone bill if the Senate strips it out of the stimulus package.

Newsweek has contacted Sanders and Sinema for comment.