Keir Starmer mocked Kemi Badenoch after she tried to attack him over an online petition demanding another general election.
More than 2.7 million people have now signed it, even though it has no practical impact on the date when the country will next go to the polls.
At PMQs in the Commons on Wednesday, the Tory leader told Starmer: “I’m the one asking the questions.
“There’s a petition out there - two million people asking him to go. He’s the one who doesn’t know how things work.”
Starmer replied: “She talks about a petition. We had a massive petition on July 4 in this country.
“We spent years taking our party from a party of protest to a party of government. They’re hurtling in the opposite direction.”
The petition, which is posted on parliament’s website, says: “I would like there to be another general election. I believe the current Labour Government have gone back on the promises they laid out in the lead up to the last election.”
After being asked about it on ITV’s This Morning on Monday, Starmer said: “I remind myself that very many people didn’t vote Labour at the last election and I’m unsurprised that many of them want a rerun.
“That isn’t how our system works. There will be plenty of people who didn’t want us in in the first place, so what I focus on is the decisions that I have to make every day.”