Olly Murs poses backstage in his waistcoat at the coronation

Olly Murs poses backstage in his waistcoat at the coronation concert

“I won’t take off my top, I have to be professional!” Olly Murs shows off his toned arms as he poses backstage in his waistcoat at the coronation concert after promising not to go on stage shirtless

Olly Murs showed off his muscular arms as he prepared to perform at the Coronation Concert in the grounds of Windsor Castle on Sunday to mark the coronation of King Charles III. to celebrate.

The 38-year-old singer was interviewed before appearing before King Charles III. and Queen Camilla and took the stage in front of 20,000 spectators.

Although Olly was happy to show off his toned physique backstage, earlier in the day he insisted he would not take off his top during his performance.

When invited to perform, he told BBC Radio 2: “It’s a bit surreal but I’m so honored. I’m on tour right now, so I only saw the stage yesterday. It’s the biggest thing in my career.

“It got the eyes of the world on it. People will remember that. It really is something special. It’s crazy. We just got an email asking me to do this!’

Looking good: But the singer, 38, was happy to show off his toned physique backstage, insisting earlier in the day he would not flog his top during his performance

Looking good: Olly Murs, 38, showed off his muscular arms as he prepared to perform at the Coronation Concert in the grounds of Windsor Castle

Born to perform: The singer was interviewed before taking the stage in front of King Charles III and Queen Camilla and a crowd of 20,000

Born to perform: The singer was interviewed before taking the stage in front of King Charles III and Queen Camilla and a crowd of 20,000

When host Dermot O’Leary joked he looked muscular, Olly replied: “I’m not going to take my top off, I have to be professional.”

Sunday’s show in Windsor will be hosted by Downton Abbey and Paddington star Hugh Bonneville.

Buckingham Palace has promised “global music icons and contemporary stars” for the big concert.

It will certainly be the highlight of the second coronation day.

Around 20,000 spectators are expected and there has been much speculation as to who will perform.

Musicians including Lionel Richie, Paloma Faith, Olly Murs, rock guitarist Steve Winwood and The Pussycat Dolls’ Nicole Scherzinger will entertain the royal family and members of the public.

Classic acts such as Andrea Bocelli, Welsh bass-baritone Sir Bryn Terfel and Chinese pianist Lang Lang are also on the programme.

Hollywood star Tom Cruise, Dynasty actress Dame Joan Collins, adventurer Bear Grylls, singer Sir Tom Jones and former Strictly Come Dancing pro Oti Mabuse will also be featured via video.

Dressed to impress: Olly looked dapper as he walked the red carpet in a white suit ahead of his performance

Dressed to impress: Olly looked dapper as he walked the red carpet in a white suit ahead of his performance

Regal: The waving King and Queen are seen from the balcony of Buckingham Palace after Saturday's coronation

Regal: The waving King and Queen are seen from the balcony of Buckingham Palace after Saturday’s coronation

The series of pre-recorded sketches will reveal little-known facts about the monarch and will also include moments from popular literary character Winnie the Pooh – seemingly a repeat of the famous moment Paddington Bear had tea with the Queen during her platinum anniversary celebrations.

Nigerian singer Tiwa Savage, DJ Pete Tong with his Ibiza Classics project and 13-year-old The Piano TV talent show winner Lucy will also perform.

Meanwhile, fashion designer Stella McCartney will deliver a spoken-word performance with a conservation theme that will reflect her and the royal’s “shared passion for environmental sustainability,” the BBC said.

Their performance will be part of a broader nature-themed section of the concert, which will also include a rendition of a 1980s hit by classic soul composer Alexis French and London-based singer-songwriter Zak Abel, along with a resident orchestra, band and choir will include.

Event: Guests gather at Windsor Castle, Berkshire where the Coronation Concert is held to celebrate the coronation of King Charles III and Queen Camilla

Event: Guests gather at Windsor Castle, Berkshire where the Coronation Concert is held to celebrate the coronation of King Charles III and Queen Camilla