LONDON — Britain wrapped up a joyful four-day tribute to Queen Elizabeth II on Sunday with street fairs, picnics and a pageant, after a star-studded Saturday night concert at Buckingham Palace that offered a pop-culture mash-up of Rod Stewart performing Neil Diamond’s singalong, “Sweet Caroline.”
Good times, as the song says, never seemed so good.
But if millions of Britons reveled in the queen’s Platinum Jubilee — or at least in the lazy pleasures of a late-spring, long weekend — it might have been a wise case of partying before the bar closes.
On Monday, Britain pivots from the queen’s 70-year reign to renewed political ructions over Prime Minister Boris Johnson, as well as to worries that the country faces “stagflation,” the double-whammy of recession and inflation that last afflicted Britain after the queen marked her Silver Jubilee in 1977.
“I’m pretty sure the jubilee atmosphere is a four-day wonder, and that the national mood will turn fairly sour again fairly quickly,” said Tim Bale, a professor of politics at Queen Mary University of London.
“It feels like we’re all waiting for something to happen,” he added. “For the storm or the dam to break. But it’s hard to predict if it will.”
The uneasy mood intruded briefly on the festivities when the comedian Lee Mack greeted 22,000 spectators at the concert, which was staged at the Queen Victoria Memorial in front of the gates to Buckingham Palace. “Finally,” he joked, “we can say the words ‘party’ and ‘gate,’ and it’s a positive.”
The crowd laughed at the reference to the long-simmering scandal over lockdown-breaking parties at 10 Downing Street, which the London tabloids have inevitably nicknamed “Partygate.”
For Mr. Johnson, who was seated behind Prince Charles and other family members in the royal box, it was the second wrist-slap of the jubilee. On Friday, boos drowned out cheers as he and his wife, Carrie, climbed the steps of St. Paul’s Cathedral for a service of thanksgiving for the queen.
The scandal looks to be flaring up again: the Sunday Times of London reported on June 4 that Mr. Johnson could face a no-confidence vote as soon as this week, with one unnamed rebel in the Conservative Party estimating that lawmakers had surpassed the threshold of 54 letters calling for a vote.
Mr. Johnson’s political obituary has been written before, including at other times during this scandal. He survived being fined by the police for violating lockdown rules, as well as the publication of an internal report on the affair, which blamed him for an alcohol-soaked culture in Downing Street.
Critics of Mr. Johnson, however, pointed to a new poll taken before a critical Parliamentary by-election in Wakefield, a longtime Labour Party district that the Conservatives won in the 2019 election on Mr. Johnson’s promise to “Get Brexit Done.” The seat, in West Yorkshire, is open because the Tory former lawmaker, Imran Ahmad Khan, was jailed on charges of child sexual assault.
The survey, conducted by the pollster James Johnson, showed Labour holding a lead of 20 percentage points over the Conservatives. Mr. Johnson, who conducted polls for former Prime Minister Theresa May, wrote on Twitter that the main reason people gave for planning to vote Labour was antipathy toward the prime minister.
If the Conservatives are swept out of that seat, as well as out of another one, in Tiverton and Honiton — where the incumbent, Neil Parish, resigned after admitting he had watched pornography on his phone while in the House of Commons — political analysts said panicky Tory lawmakers would trigger a no-confidence vote.
Even if Mr. Johnson survives that, some predict he will face a winter of misery, as the country deals with surging food and fuel prices. The International Monetary Fund estimated last month that consumer prices would soar 13 percent this year and next. Other forecasters said a recession was unavoidable.
With all that looming, Britons could be forgiven for dwelling on the last 70 years, an era in which the queen anchored the country through previous bouts of political, economic and social turbulence.
Some Key Moments in Queen Elizabeth’s Reign
“You laugh and cry with us and, most importantly, have been there for us, for these 70 years,” said Prince Charles, who spoke at the concert and referred to his 96-year-old mother as “Her Majesty” and “Mummy.”
On Sunday, the queen, clad in green, made another appearance on the balcony at Buckingham Palace, after missing most of the festivities because of trouble walking. A crowd of several thousand saluted her with “God Save the Queen.”
At the concert the night before, Elizabeth stole the show with a prerecorded sequence in which she shared a mishap-prone cream tea with Paddington Bear, voiced by the actor Ben Whishaw.
The two bonded over their love of marmalade sandwiches, with the queen pulling one out of her handbag. Then, clicking spoons rhythmically against their teacups, they sounded the familiar opening drumbeat of “We Will Rock You,” as the British band Queen began playing their hit song on the stage.
The sequence was reminiscent of the 2012 Olympic Games, which featured an even more elaborate sketch of the queen and James Bond, played by Daniel Craig, parachuting into the stadium from a helicopter during the opening ceremony.
On Sunday, a carnival, with marching bands and dragons, filled the square where Diana Ross, Alicia Keys and Duran Duran had performed. In towns across Britain, residents set out tables, wrapped in red-white-and-blue bunting, and served cucumber sandwiches and Pimm’s cocktails to their neighbors.
“It’s a great opportunity to connect people who wouldn’t know each other,” said Alina Wallace, who works in public relations and had prepared a jar of gin and grapefruit in London’s Honeybrook Road.
A few streets away, Hannah Stanislaus stood behind a table filled with cheese scones, Victoria sandwich sponge cake, muffins, shortbread and fruit cake. In the past four days, she said, she had attended four street parties.
“It’s the official comeback of the British people after Covid,” she said. “The jubilee has given a chance to people to reconcile.”
Emma Bubola contributed reporting.