Under the deal, Gibraltar will not officially join the zone, made up of 29 mainly EU countries including Spain.
Instead, Spanish authorities will carry out “second line” Schengen-style border checks in a special zone, after border checks conducted by Gibraltarian officials.
Spanish guards will have powers to arrest, search and interview travellers “where it is justified in the course of border control,” according to the treaty.
The system should eventually allow for the removal of border infrastructure at Gibraltar’s land border with Spain, which is crossed every day by around half of the Rock’s workforce.
The UK government is likening the new system to that in operation at London’s St Pancras station, where Eurostar passengers are checked by both British and French officials before boarding trains for the continent.
