London (AFP) - British superstar Ed Sheeran brings the curtain down on Sunday on four days of momentous nationwide celebrations of Queen Elizabeth II's historic Platinum Jubilee, in a finale filled with picnics, pomp and pop.
The multi-award-winning singer-songwriter will wrap up a day-long pageant lauding the 96-year-old monarch's record seven decades on the throne, as the long weekend of festivities featuring a multitude of tributes across the UK concludes.
Sheeran is one of numerous "national treasures" poised to perform a "special tribute" to the queen against the backdrop of Buckingham Palace to mark a milestone never previously reached by a British sovereign.
Meanwhile, millions of people are expected to defy gloomy weather forecasts for much of the country and attend "Big Jubilee Lunch" picnics, including an attempted world record for the longest street party.
It remains unclear if the queen will attend any parts of the pageant in person, after being forced to skip several Platinum Jubilee celebration appearances due to mobility issues.
At a music concert outside the palace on Saturday night, the monarch made a surprise on-screen appearance, taking tea with the beloved children's book and film character Paddington Bear.
In the pre-recorded scene she tapped out the drumbeat of rock band Queen's "We Will Rock You" -- the concert's opening number -- on a fine china teacup and saucer to get the party started.
'Mummy'
The four days of royal celebrations saw Thursday and Friday designated public holidays.
Longer pub opening hours, street parties and other events heralding the queen have been credited with temporarily lifting the gloom of Britain's worsening cost-of-living crisis.
The official programme kicked off on Thursday with the pomp-filled Trooping the Colour military parade.The queen made two public appearances to huge crowds on the Buckingham Palace balcony, followed by another later in Windsor.
Friday's focus was a traditional Church of England service of thanksgiving led by senior royals -- including returning Prince Harry and his wife Meghan -- in St Paul's Cathedral in London.
Then on Saturday the tone turned more celebratory as Motown diva Diana Ross and Italian opera legend Andrea Bocelli led the star-studded "Platinum Party" outside Buckingham Palace.
Prince Charles and his son Prince William paid highly personal tributes to the queen during the nearly three-hour concert, which she watched on TV from Windsor.
"You pledged to serve your whole life -- you continue to deliver," Charles said in his poignant message to "Mummy", which he capped by calling for "three cheers to Her Majesty".
Sunday newspapers applauded the spectacle."Nobody does pomp, ceremony and flypasts as we do," The Sunday Times wrote.
"Anybody selling holidays to foreign tourists will have had a field day.The images of Britain sent around the world have been priceless."
The Sunday Telegraph said the jubilee had "a valedictory feel" but added: "There is also keen awareness that we will never see the likes of this monarch again."
The Observer called it "part of a long goodbye" that began with her husband Prince Philip's funeral last year.
Spectacle
Sunday's four-part "Platinum Jubilee Pageant" starts with a military spectacle celebrating the armed forces, along with personnel from many of the other 53 Commonwealth countries that the queen heads.
The Mounted Band of the Household Cavalry -- the largest regular military band in the UK -- will lead the 260-year-old Gold State Coach along a crowd-thronged route to Buckingham Palace.
A cast of 10,000 then stages a street performance showcasing popular culture over the seven decades, featuring music, dance, fashion, youth culture and classic cars.
Performers from street theatre, carnival and other genres also join in to celebrate Elizabeth II's extraordinary life.
Highlights include an aerial artist suspended under a vast helium balloon, known as a heliosphere, bearing the sovereign's image.
The carnival will include a giant oak tree flanked with maypole dancers, a huge moving wedding cake sounding out Bollywood hits, a towering dragon and beasts three storeys tall.
The spectacle will culminate in the singing of Britain's national anthem, "God Save the Queen", and Sheeran.
'Full circle'
Earlier on Sunday, up to 10 million people are expected to take part in the Big Jubilee Lunch picnics nationwide.
More than 70,000 have registered to host such picnics in villages, town and cities, with families, neighbours and entire communities set to come together to share food and drink.
More than 600 lunches have also been planned throughout the Commonwealth and beyond, from Canada to Brazil, New Zealand to Japan and South Africa to Switzerland.
A flagship feast with specially invited guests will take place at The Oval cricket ground in London.
Sheeran, 31, will then crown things off by singing his 2017 hit "Perfect".
Ahead of his appearance, the "Shape of You" singer-songwriter revealed that the 2002 "Party at the Palace" to mark the queen's Golden Jubilee actually inspired his phenomenally successful musical career.
Watching on television, he saw Eric Clapton play his classic song "Layla" and decided "That's what I wanna do", he wrote on Instagram.
Sheeran went on to perform at the queen's Diamond Jubilee concert 10 years ago.
"Life is weird how it keeps coming full circle in lovely ways," he added.
