The Democratic speaker of the US House, Nancy Pelosi, said she “fears for democracy” if Republicans retake the chamber in November.

“It is absolutely essential for our democracy that we win,” Pelosi said in an interview during the 2022 Toner Prizes for political journalism on Monday night.

“I fear for our democracy if the Republicans were ever to get the gavel. We can’t let that happen. Democracy is on the ballot in November.”

Parties that control the White House usually receive a rebuke from voters in the first midterms after a presidential election. With Joe Biden’s poll numbers in the gutter and his administration facing strong economic headwinds and grappling with the crisis in Ukraine, Republicans are widely favored to win back the House and perhaps the Senate this year.

Kevin McCarthy, the House minority leader, told Punchbowl News last week: “We’re going to win the majority, and it’s not going to be a five-seat majority.”

In the Senate, Ron Johnson, from Wisconsin, has indicated how Republicans are looking forward to controlling committees and wielding subpoena power. The GOP, Johnson said, will be “like a mosquito in a nudist colony, it’s a target-rich environment”.

Johnson indicated a desire to investigate the federal coronavirus response and the business dealings of Hunter Biden, the president’s son. Most observers expect House Republicans to scrap the committee investigating Donald Trump’s attempts to overturn his election defeat and the Capitol attack that followed.

But Pelosi said: “I don’t have any intention of the Democrats losing the Congress in November.”

Rejecting “so-called conventional wisdom” about midterm elections, the speaker said: “There’s nothing conventional anymore, because of the way people communicate with social media and how they receive their information, how they are called to action, how they’re called to meetings and the rest is quite different. So any past assumptions about elections are obsolete.”

“We do have a plan,” she added. “We have a vision of the victory. We will plan to get it done and we’re going to own the ground.”

Pelosi also cast doubt on the accuracy of polling about Biden’s favourability and said redistricting, a process widely thought to favour Republicans, who control more state governments, would not necessarily leave Democrats at a disadvantage.

“Everybody said redistricting was going to be horrible for the Democrats,” Pelosi said. “Remember that? Not so. Not so. If anything, we’ll pick up seats rather than lose 10 to 15, which conventional wisdom said that we would. There’s nothing conventional anymore, and it certainly ain’t wisdom.

“And nobody’s going to be rejecting the president.”