The Spice Girls are set for a huge reunion concert this autumn - six years after they split.

All five former members of the Girl Power phenomenon are said to be agreed in principle to a charity concert in London followed by a national tour.

The reunion comes after the success of the Take That revival. The girls would appear with Nineties band Boyzone, who are also reforming, according to industry figures.

"They are really keen to do it if there is a charity angle. They are talking about doing it for Bono's Red campaign. It's been on the cards for a while, at least a couple of months. They are all good friends now," said one source.

Senior executives at TV production company Emap TV, who want to broadcast the concert, are flying to Los Angeles this weekend for detailed talks with Simon Fuller, the band's former manager, who still represents Victoria Beckham.

One sticking point is said to be their £ 2.5 million- a- head demands for the broadcast rights to the charity concert and tour. Ticket receipts for the concert itself would go to charity.

Details of the concert are still being negotiated but it would have to be after the birth of Baby Spice Emma Bunton's first baby in the summer. Scary Spice Melanie Brown is also due to give birth in March. Ginger Spice Geri Halliwell had a daughter, Bluebell Madonna last May. The fifth member is Sporty Spice Melanie Chisholm.

The plans involve a concert at a huge London venue, possibly Hyde Park, in September or October.

It will be 11 years after the Spice Girls exploded on to the pop scene with their debut single Wannabe, still the biggest selling single by an all-female group. A further eight No 1s followed before they broke up in February 2001 after record sales of 55 million. Halliwell left the band in 1998. The Beckhams are close to U2 front man Bono, whose Red campaign raises money to help victims of Aids. Last year David appeared in a TV advert for the Motorola's Red Razr mobile phone, which generates a contribution to the charity every time it is used.

There have been a succession of rumours about a reunion, particularly at the time of the Live 8 concert in 2005. Earlier this month Beckham, Bunton and Halliwell were spotted having dinner together at Nobu restaurant in London, leading to renewed speculation.

Bunton was recently asked about a reunion on the Richard and Judy TV show and replied: "I would love to. Even the other girls have said they'd love to do it. It would be great."