The case is yet to begin, but yesterday O2 sought an injunction preventing 3 from using the imagery in the meantime. However, the judge refused to grant the injunction and said there were arguments for both sides of the case.
O2 is suing 3 owner Hutchison 3G UK for trademark infringement and dishonest advertising.
It claims that the comparisons 3 has made between the two pay-as-you-go services are unfair.
O2's advertising recently scored at the IPA Effectiveness Awards with Vallance Carruthers Coleman Priest scooping the Grand Prix for its relaunch campaign for the mobile network.
MMO2 has used the oxygen bubbles for its advertising since 2001 with the a voice over provided by 'The Lord of the Rings' actor Sean Bean.
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