3 UK plans see its four UK rivals in court next week in the opener to what might turn into a £250m case, accusing them of making it difficult to customers to switch to the upstart network.

The Times reports that 3, in a High Court action, claims Vodafone, T-mobile, Orange and O2 colluded in an effort to withhold the details customers needed to switch operators while keeping their phone numbers. They are also accused of abusing their dominant market position.

3, a comparative newcomer to the UK mobile market with teeny tiny market share, is reportedly asking for a two day hearing before a commercial judge to force its rivals to hand over four years' worth of documents which will back up its argument, the report says.

The case emerged as Ofcom yesterday put in place new rules to make sure number porting is a two hour process by 2009. The industry plans to move to a two day max early next year.

A spokesman for O2 said the firm couldn’t make any comment on the legal proceedings. But he pointed to the Ofcom decision yesterday, saying the industry was already moving to smooth the process of porting numbers.

However, he said, O2 was not convinced that dropping from two days to two hours was in the best interests of consumers, saying there are “worries about an increase in slamming” as a result. Slamming its the practice of switching customers from one provider to another without their express consent.

A Vodafone spokeswoman said next week’s case was purely centred on whether 3 could get access to rivals’ documents, before it made a decision on whether to go ahead with full scale legal action.

She highlighted the Ofcom move this week, but questioned whether the move to a two hour porting period was a good thing for consumers, saying it would mean more expense somewhere down the line, and raised concerns about “slamming”.

Orange and T-Mobile were unavailable to comment. But we’re pretty sure we know what they would have said. ®

Related stories

• T-Mobile not alone in spinning price hikes (30 June 2008)
• Ofcom sets new deadline for mobile number porting (30 November 2007)
• Moving mobile numbers should be instant (18 July 2007)