Terrorist Asset-Freezing etc. Bill [HL]

Following the point just made by the noble and learned Lord, Lord Lloyd, if the Bill were to place the responsibility on the Treasury not to designate but to seek an ex parte decision by a judge to designate, would that hearing not be held in camera? In those circumstances, would it not be possible to provide, for example, evidence from the security services, such as SIS and GCHQ, without any danger to national security?