ABBA stars surprise Mamma Mia! audience on musical's anniversary

ABBA’s two leading men made a surprise appearance on stage as hit musical Mamma Mia! celebrated its 20th anniversary.

Benny Andersson and Bjorn Ulvaeus, one half of the Swedish pop sensation, delighted the audience as the ABBA-inspired show marked two decades in the West End.

The pair were greeted with huge applause and cheers from a packed Novello Theatre in London when they took to the stage after the show.

Ulvaeus thanked the “fantastic audience” and told them it was “both strange and wonderful to be on this stage tonight”.

The ABBA stars, who wrote the music and lyrics to the musical, were joined by producer Judy Craymer, director Phyllida Lloyd and writer Catherine Johnson.

Ulvaeus described the women as “three angels”.

Celebratory confetti rained down on the audience during a medley of ABBA classics including Dancing Queen and Waterloo.

Andersson said backstage it had been “too long” since he had seen the show and that he felt moved on the anniversary.

The songwriter praised the cast as “wonderful” and added: “There is a chance to be immersed, to get moved, and I was tonight and I’m happy I can feel that.”

Mamma Mia! is a feel-good tale centred around a mother, daughter and three possible fathers on an idyllic Greek island.

It unfolds to ABBA’s timeless pop classics and has now been seen live on stage by 65 million people around the world.

Mamma Mia! was adapted for the silver screen in 2008 and starred Meryl Streep, Amanda Seyfried, Pierce Brosnan and Colin Firth.

The film cast returned for the sequel Mamma Mia! Here We Go Again in 2018.

The London stage show, which has been seen by more than nine million people during 8,000 performances, originally opened at the capital’s Prince Edward Theatre in April 1999.

It was transferred to the Prince of Wales Theatre in 2004 before heading to its current home in 2012.

The musical has been seen in 50 productions in 16 different languages around the world, grossing more than $4bn (£3.07bn) at box offices.

ABBA announced in April 2018 that they were reuniting to release new music for the first time in 35 years.