Cooper Parry, an East Midlands-based accounting and business advisory firm, attempted to file an injunction against Barclays' campaign because it uses the line: "Now there's a thought." Cooper Parry has been using the same line for the past five years.
The advertising, launched by Bartle Bogle Hegarty last week, replaced Barclays' "fluent in finance" campaign.
An immediate injunction, which would have halted the campaign instantly, was not granted. However, the judge deemed the case serious enough to warrant a quick trial, which will begin on 12 December.
Jeremy Bowler, the chief executive at Cooper Parry, said: "The judge described the issue as 'a significantly urgent matter to justify an early trial'. We did ask for an injunction to stop Barclays but we now have the opportunity to stop them before Christmas. We achieved what we expected."
The company claims Barclays asked permission to use the strapline last month. However, Cooper Parry refused, saying that the line was core to its business.