Though not a technical term, this phrase has passed into legal anecdotal history through its use by Ward LJ in the opening lines of a judgment:

“This case involves a number of – and here I must not fall into Dr Spooner’s error – warring bankers.”

The case in which he said this does not seem to have been published, let alone reported, but his fellow Lord Justice the late Sir Henry Brooke in his blog attributed it to the judgment granting leave to appeal in Royal Bank of Scotland v Highland Financial Partners [2011] EWCA Civ 475.

However, it was not the first time Ward LJ had used the expression. In the earlier case of Manson v Vooght (unreported) 12 June 1998 he had used it (without any reference to spoonerisms) when granting leave to appeal:

“The point arises in this way. Mr. Manson is a much aggrieved gentleman, whose burning sense of injustice arises out of the fact that the company, of which he was the major shareholder and managing director, was a company in some financial distress in 1988. He sought the advice of the first defendant, Mr. Vooght, as to how to deal with his battle with warring bankers. He engaged Mr. Vooght whose advice was that the company should be put into receivership.”