"...if a person agrees with any other person or persons that a course of conduct shall be pursued which, if the agreement is carried out in accordance with their intentions, either -
(a) will necessarily amount to or involve the commission of any offence or offences by one or more of the parties to the agreement, or
(b) would do so but for the existence of facts which render the commission of the offence or any of the offences impossible, [added by S.5 Criminal Attempts Act 1981]
he is guilty of conspiracy to commit the offence or offences in question."