Joe Biden, who has been criticised for failing to use his “bully pulpit” to defend voting rights, is set to deliver on Tuesday an aggressive denunciation of Donald Trump’s “big lie” about a stolen election.

After months of sidestepping acrimony with his predecessor in a bid to lower the political temperature, Biden will argue that Trump’s false conspiracy theories led to the 6 January insurrection and a rash of voter restrictions, the White House said.

“He’ll lay out the moral case for why denying the right to vote is a form of suppression and a form of silencing,” said Jen Psaki, the White House press secretary, to reporters on Monday.

“And he will redouble his commitment to using every tool at his disposal to continue to fight to protect the fundamental right of Americans to vote against the onslaught of voter suppression laws, based on a dangerous and discredited conspiracy theory that culminated in an assault on our Capitol.”

Biden will deliver the remarks in Philadelphia, symbolically important as the birthplace of American democracy; a democracy now seen as being under existential threat from numerous Republican state legislatures passing voter suppression bills.

Psaki continued: “He’ll call out – the greatest irony of ‘the big lie’ is that no election in our history has met such a high standard, with over 80 judges, including those appointed by his predecessor, throwing out all challenges.

“He’ll also decry efforts to strip the right to vote as authoritarian and anti-American, and stand up against the notion that politicians should be allowed to choose their voters or to subvert our system by replacing independent election authorities with partisan ones.”

Biden will highlight the “need to work together with civil rights organizations to build as broad a turnout and voter education system to overcome the worst challenge to our democracy since the civil war,” the press secretary added.

Trump’s false claim of voter fraud last year was dismissed as baseless by his own attorney general, William Barr, as well as dozens of judges and state election officials. Yet the ex-president has pushed it repeatedly, and again on Sunday during a speech to the Conservative Political Action Conference in Dallas, Texas. It continues to thrive in rightwing media and among his support base.

This will be Biden’s first major speech on voting rights since the For the People Act, a sweeping reform aiming to shore up democracy, stalled in the Senate when Republicans deployed the filibuster, and since the supreme court upheld restrictive voting rules in Arizona.

The president, who met civil rights leaders at the White House last Thursday, has been condemned for not speaking out more forcefully to support the For the People Act or to sound the alarm about the dangers to voting rights.

Ezra Levin, co-executive director of the grassroots movement Indivisible, tweeted last week: “We all worked our butts off to elect Biden, and I desperately want him to succeed. But we didn’t put him in the game just to see him sit on the sidelines. We need our star player on the field.”

Progressives have urged Biden and moderate Democrats to support changing or abolishing the filibuster, which requires 60 votes for legislation to advance; the Senate is currently divided 50-50 between Democrats and Republicans. James Clyburn, a Democratic congressman and staunch Biden ally, has proposed an exemption to the filibuster for voting rights.

But Psaki told reporters: “The filibuster is a legislative process tool – an important one – that warrants debate, but determination about making changes will be made by members of the Senate, not by this president or any president, frankly, moving forward. And it requires every single Democrat supporting changes.

“Now, I’m not here to provide a whip count for all of you, but that’s not where support currently stands. So, the president’s view continues to be aligned with what he has said in the past, which that he has not supported the elimination of the filibuster because it has been used, as often, the other way around.”

Regarding an exemption for voting rights, Psaki said, “we don’t have any new position on that either”.