The degree and nature of any Spanish presence to supervise Frontex at Gibraltar's entry points is still being negotiated in treaty talks.
This is because Spain will have the responsibility for the Schengen checks, as people enter the zone via Gibraltar's port and airport.
However, speaking on GBC’s Viewpoint programme, Sir David Steel stressed that if this is to be a physical presence, which is not confirmed, then it must not infringe on Gibraltar’s sovereignty.
Viewpoint airs Thursday at 9.30pm. Watch again on gbc.gi/viewpoint.
TREATY: Degree & nature of Spain's presence in Gibraltar to supervise...