h olding answer
There have been no such discussions. Operational tactics when using firearms are a matter for the police. The use of firearms by the police is closely governed by Guidelines produced by the Association of Chief Police Officers (available at):
Chief Officers must decide in any given circumstances whether armed officers should be authorised to use their firearms. Once authorised to use firearms, it is for the individual officer to ensure they act within the law. The Criminal Law Act 1967 provides that the police may use such force as is reasonable in the circumstances to effect an arrest or to prevent crime.