THE makers called it the feelgood event of the summer. But even they couldn't have predicted just how big the film of the smash hit musical Mamma Mia! would become.

While the rain poured down, moviegoers poured in to see the musical about a family wedding set on a Greek island, featuring Pierce Brosnan and Meryl Streep, based on the music of Abba.

The film took £5.2 million on its first week in the UK and is still selling out. In many cinemas you have to book days ahead to get a seat and in others there have been reports of bookings systems crashing and arguments breaking out when moviegoers turn up and find they can't get in.

Outside the Westover Road Odeon in Bournemouth on Thursday, fans were gathering to buy their Mamma Mia! tickets.

"It's fantastic, I love it," said Lindi from Charminster, who was there with a friend.

"It's a lovely, lovely film," said Emma Barton, who is on holiday in Bournemouth with her family and who was seeing the film for the second time.

Since its release last month, Mamma Mia! has become the fastest-grossing musical of all time, the highest-grossing film of the year in the UK, Austria, Greece, Hungary, Norway and Sweden, and the number one album on Billboard's Top 200 album chart.

A spokeswoman for Bournemouth's Odeon Cinema in Westover Road agreed it was a phenomenon.

"We thought it would be popular but we didn't realise by how much. People have come to see it, then come back again and some are on their third visit. They're telling their friends and they're going back and bringing in their granny and their grand-child."

Enthusiastic filmgoers are dancing in the aisles and many are now looking forward to the imminent release of the singalong version, where the words to hits like Money, Money Money and Dancing Queen will be flashed up.

"If you walk past the doors you can hear them all singing along anyway," she said. "We'll keep showing it for as long as people want it."

Wendy Frewer, of Wimborne's independent Tivoli Theatre, is thrilled with the show, too.

"It's an absolute phenomenon," she says. "We have been sold out for every performance and my staff have been rushed off their feet.

"The audience are in there singing and dancing and even at the end, it's hard to get them to leave.

"This afternoon's performance started at 2.30pm. But we had people queuing at 12.45 to ensure they got a good seat."

She says women are coming to see the show and then immediately re-booking to bring their children and parents along. "It's a real family affair."

Why is it so popular?

"It's just a happy, lovely film with beautiful scenery," she says.

Is it true that many people are using it as a bit of escapism after this summer's dreadful weather? "I bet they are!"

Mamma Mia is so good for business, in fact, that the Tivoli are having it back again. "We've just opened booking for the week of September 5," says Wendy.

All this is a long way from the film's release when it was trashed by the critics (Rolling Stone magazine described it as clumsy and overwrought) and the shaky singing talents of its stars, Streep, Brosnan and Julie Walters were sneered at.

But even this has proved a triumph. One fan told a website: "They sing it like anyone would - that's part of the charm."