Joe Manchin, the moderate Democrat standing in the way of Joe Biden’s signature $3.5tn spending bill, insisted again on Sunday he would not support the package, declaring the price tag too high and White House efforts to speed its passage too hasty.

The West Virginia senator, who earlier this month urged the administration to “hit the pause button” on the ambitious measure, is the swing vote in a divided 50-50 chamber. Last week, Ronald Klain, the White House chief of staff, said he thought Manchin was “very persuadable”, while Chuck Schumer, the Democratic Senate majority leader, said the budget reconciliation bill was “full speed ahead”.

But in appearances Sunday on two political talkshows, Manchin reiterated his opposition, telling ABC’s This Week: “I cannot support $3.5tn. If I can’t go home and explain [the bill], I can’t vote for it.

“There’s not a rush to do that right now. We don’t have an urgency. Don’t you think we ought to debate a little bit more, talk about it, and see what we’ve got out there?”

Manchin did not say what figure he thought would be an acceptable federal investment in the bill, which targets healthcare, immigration reform and efforts to counter the climate crisis among other social priorities and programs. But in private discussions with colleagues he is reported to have floated a total of $1tn to $1.5tn.

His resistance has drawn the ire of progressives in his own caucus, including some House Democrats who are threatening to block a smaller, bipartisan $1tn infrastructure bill that has already passed the Senate unless Manchin gives way.

Bernie Sanders, the Vermont senator and Senate budget committee chair who has said $3.5tn was “already the result of a major, major compromise”, urged Manchin to reconsider.

“You have an overwhelming majority of working families in America who want us to do this. You have the president, you have over 90% of the people in the House, over 90% of senators,” Sanders said in his own appearance on This Week.

“Is it appropriate for one person to destroy two pieces of legislation? Joe Manchin has the right to get his views heard. He has to sit down with all of us and we’ll work it out. It would really be a terrible, terrible shame for the American people if both bills went down.”

Manchin also spoke out against one of his most vocal critics in the House, the New York congresswoman Alexandria Ocasio-Cortez, who has criticized his perceived opposition to spending money on social and infrastructure programs while at the same time being close to the fossil fuel industry.

“[I’m] sick of this ‘bipartisan’ corruption that masquerades as clear-eyed moderation,” she wrote in a tweet earlier this month, asserting that Manchin held weekly “huddles” with the oil company Exxon, and that “so-called ‘bipartisan’ fossil fuel bills” were “killing people”.

On CNN’s State of the Union on Sunday, Manchin denied the allegation. “I keep my door open for everybody, it’s totally false,” he said.

“Those type of superlatives are just awful. I don’t know the young lady, I’ve met her one time. She’s just speculating.”

Of the House Democrats’ threat to derail the infrastructure bill, he said: “They have to do what they have to do. If they play politics with the needs of America, I can tell you America will recoil.”