Former Spice Girl Geri Halliwell is expected to testify in the High Court on Friday.

The 27-year-old former Ginger Spice is giving evidence in a complex legal action between the group and the official sponsors of their 1998 world tour.

Italian motorcycle manufacturers Aprilia say her departure from the group in May 1998 cost them £1.6m in lost profits.

The pop act signed a £500,000 contract with Aprilia to promote their products, including a special Spice Sonic scooter with a picture of all Spice Girls on it.

Ms Halliwell, who has carved out her own career as a solo singer, will step into the same witness box as Baby Spice Emma Bunton, who gave evidence on Wednesday.

But the company says the promotion turned into a "total marketing flop" when Ms Halliwell left.

Aprilia claims the group, which is suing the company for £212,000 in unpaid sponsorship and royalty fees, was already aware of Ms Halliwell's plans to quit when they signed the contract.

'We never thought she'd leave'

On Wednesday Ms Bunton told a packed court the Spice Girls never believed Ms Halliwell would ever leave the group despite occasional comments to that effect.

She said the pop phenomenon were "as strong as ever" after Ms Halliwell's departure.

Friday's hearing is expected to be played out in front of a public gallery packed with Spice Girls fans, anxious to find out what lay behind Ms Halliwell's departure.

Meanwhile, Ms Halliwell has said she will not be joining her former colleagues when they receive an outstanding achievement award at next month's Brits.

She said: "The Spice Girls were and are a remarkable band, and I will always be proud of our achievements.

"I do not, however, feel it would be appropriate for me to join the girls to receive the award as I am no longer an active member of the band. This is their moment in the spotlight and they deserve it."