Lord Bridge in R v Anderson suggested a different form of MR is required:
'Beyond the mere fact of agreement, the necessary MR of the crime is, in my opinion, established if, and only if, it is shown that the accused, when he entered into the agreement, intended to play some part in the agreed course of conduct in furtherance of the criminal purpose which the agreed course of conduct was intended to achieve. Nothing less will suffice; nothing more is required.'
Anderson was thus covered as he intended to supply the wire cutting equipment.
But this MR definition causes the problem that a mastermind who plans for a crime, reaping the benefits, but who does not wish to put himself at risk in carrying it out, cannot be convicted of conspiracy if the plan does not go ahead.
The COA was not keen to allow this and interpreted this definition very broadly in R v Siracusa (1990).