The Relations Between Gibraltar and the EU: Brexit à la Carte!

Brexit lead to a complete revision of the relationship between the United Kingdom (UK) and the European Union (EU). It particularly affected regions sharing a land border between the UK and the EU, such as Northern Ireland and Gibraltar. In particular, in relation to the latter, a substantial departure from Brexit was noted in light of the June 2025 EU–UK–Spain–Gibraltar political agreement. This stipulates a wide array of measure to be undertaken. For example the agreement removes routine border checks between Gibraltar and Spain, places Schengen-area controls under Spanish responsibility at Gibraltar’s points of entry, and envisages progressive customs and indirect-tax alignment and co-operation on migration, policing and fiscal transparency. This paper focuses in greater detail on two interlocking challenges the agreement poses to the premises of Brexit, namely: (1) functional re-integration of a territory outside the UK–EU trade and regulatory frameworks; (2) the emergence of hybrid governance mechanisms that complicate the UK’s claim to its post-Brexit sovereignty. It focuses in particular on two issue fields, the Schengen area controls and the customs and taxation. As such, the paper aims to address whether the case of Gibraltar can be seen as targeted reintegration and whether such a move puts into question the formal separation as envisioned by Brexiteers.