Mamma Mia! How can we resist you?

It didn’t really matter that the plot was rather flimsy and the singing of some of the Hollywood stars was pretty ordinary. What’s surprising is that it’s taken a decade for the long-awaited sequel, Mamma Mia! Here We Go Again, to hit our screens.

The entire original cast has been re-assembled and this time around 72-year-old Cher will join the beach party as Sophie, again played by Amanda Seyfried, returns to her Greek island home pregnant and alone. The Mamma Mia! franchise has become a £2billion global phenomenon.

In the UK the DVD of the film is owned by an estimated one in four households, while the stage musical is the fourth highest grossing Broadway show in history raking in £500million. Mamma Mia! also spawned a hit album, almost single-handedly reinvigorated tourism to the Greek islands and created a new generation of Abba fans.

Although the appeal might seem obvious there have even been books by academics seeking to explain exactly why the world is so enraptured with Mamma Mia! And this time round there is an added frisson because the Swedish super group comprising Agnetha, Benny, Bjorn and Anni-Frid, is back in the studio recording again after a 35-year absence.

It began in 1999 when the musical, which has been seen by 60 million people and has earned £1.5billion at the box office worldwide, first hit the West End. The stage show was the brainchild of British producer Judy Craymer, who met Benny and Bjorn as they worked on the musical Chess.

It took a while to persuade the pair to collaborate on a show based on the group’s songs because they feared a flop would tarnish the Abba legacy. They needn’t have worried. Mamma Mia! opened on Broadway two years later and ran for 14 years.

It has since been performed in more than 50 countries, from South Korea to Qatar, and been translated into 22 languages. Named after a 1975 Abba chart topper, Mamma Mia! tells the story of newly engaged Sophie who is determined to find her father and – to the surprise of mother Donna – invites the three possible candidates to her wedding.

It is packed with all the band’s hits such as Dancing Queen, Knowing Me, Knowing You and The Winner Takes It All. Craymer, who has reportedly made £90million from the franchise, also worked on the 2008 film which starred Meryl Streep, Pierce Brosnan, Colin Firth, Dominic Cooper, Julie Walters and Stellan Skarsgard.

The casting of Brosnan, a former James Bond, in a comedy musical raised eyebrows and some of the singing by the leads wasn’t to everyone’s taste. Indeed none of the male leads had any singing history, while Oscar-winner Streep was also taking a leap into the unknown when it came to holding a tune.

“They were primarily chosen for their qualities as actors,” said Abba’s Benny at the time.

“But if they hadn’t been able to sing they wouldn’t have got the parts.”

Firth, who’d never sung outside the shower, admits now: “There was a fantastic kind of recklessness to making the first film.

“I think dignity can be a little overrated so I relished making a fool of myself with all these serious actors. But every time we finished a take we would look at one another and wonder what on earth we were doing. Committing career suicide?”

Skarsgard recalls: “I saw the pain in Benny’s eyes and his ears as I was slaughtering an Abba song.”

Cue barbs about the Hollywood stars meeting their Waterloo, with one harsh critic concluding that all that was wrong with Mamma Mia! was the singing, the dancing and the acting. Another noted that Walters’s rendition of Take A Chance On Me could “clear the average bingo hall” and the film was branded “a Super Pooper”.

But audiences adored the movie, which was shot on the Aegean island of Skopelos and at Pinewood studios, for its foot-tapping exuberance. Perhaps the real stars were the idyllic setting and the 24 Abba hits packed into two hours.

It’s also been suggested that the timing of the release at the height of the 2008 global recession was an accidental master stroke because everyone was looking for the escapism which Mamma Mia! delivered in spades.

The introduction of sing-along versions, with lyrics on the screen, only added to the appeal. At one stage Mamma Mia! was only second behind Titanic in the list of highest-grossing films in British cinema history, while the DVD sold 1.7million copies on its first day.

Everything connected with Mamma Mia! has been a licence to print Money, Money, Money. To the dismay of Greek tourism bosses the big screen follow-up was actually filmed on the Croatian island of Vis for tax reasons.

The new film includes Abba tracks not heard in the fi rst movie, plus many old favourites. Cher, who plays Sophie’s grandmother, will be seen belting out Fernando. Here We Go Again uses flashbacks to explore the back story of Streep’s character and another newcomer is British actress Lily James playing the young Donna.

However it was the arrival of Richard Curtis, of Four Weddings And A Funeral and Love Actually fame, as scriptwriter that finally got the eagerly-anticipated sequel off the ground.

Walters, who was made a dame during filming last year, says: “My first reaction when my agent told me they were going to make a second one was, ‘Oh God, no, it’s going to be awful’. But the script was so good I think it’s better. I think the songs fit more naturally with the story.”

Benny Andersson, who along with Bjorn Ulvaeus makes up the song-writing team at Abba’s core, was also initially reluctant.

“Why? Because the first one was so good,” says Benny, who first shot to fame in 1974 when the group won the Eurovision Song Contest. But he was eventually persuaded and is an executive producer.

“We read the script and everyone said, ‘Yes, we want to do this,’” adds the Swede, who, like Bjorn, will again have a cameo role. Last time round Brosnan’s singing was likened to a braying donkey and a wounded racoon. Asked if there’s been an improvement Benny laughs:

“He’s fine, like last time. It’s just you British that think it’s funny that James Bond is singing something romantic.”

Already it’s being predicted that Here We Go Again will surpass the box office success of the original.

It seems not even 007’s dodgy voice can stop the Mamma Mia! juggernaut from rolling along.