When allegations first emerged in November about parties held at 10 Downing Street, the residence and offices of the British prime minister, during a strict Covid lockdown, Prime Minister Boris Johnson waved them away. Yet in the weeks since, the scandal has only grown, with public outrage building as more instances and details of lockdown parties at Downing Street have emerged.Some voters in Britain have long been willing to overlook the foibles of Mr. Johnson’s character, but this is a scandal that poses an existential threat to his leadership. Guest: Mark Landler, the London bureau chief for The New York Times.Want more from The Daily? For one big idea on the news each week from our team, subscribe to our newsletter. Background reading: Boris Johnson’s future is in doubt after two humiliating apologies about parties while the country was under Covid restrictions. Here’s a guide to how he could be forced out, or fight on.Mr. Johnson, long famed for brushing off accusations of distortion or outright lying that seemed to only bolster his image as an incorrigible scamp, suddenly faces potential political death over the very charge to which he had seemed immune.For more information on today’s episode, visit nytimes.com/thedaily. Transcripts of each episode will be made available by the next workday.