The lawsuit was brought by British consumer champion Justin Gutmann on behalf of around 24 million iPhone users in the United Kingdom. Gutmann want damages from Apple on their behalf of up to $1.9 billion plus interest.

His lawyers argued Apple concealed issues with batteries in certain phone models by "throttling" them with software updates and installed a power management tool which limited performance.

Apple, claimed the lawsuit was "baseless" and strongly denied batteries in iPhones were defective, apart from in a small number of iPhone 6s models for which it offered free battery replacements.

The company sought to get the case thrown out of court, but the Competition Appeal Tribunal (CAT) said Gutmann's case can proceed in a written ruling.