Days later – as the overseas territory was from becoming the only land border marked by a hard Brexit – Madrid and London on an agreement in principle that championed the idea of incorporating the British territory into the EU’s Schengen area.

Source: https://www.theguardian.com/world/2023/jan/02/spain-ready-for-any-scenario-as-gibraltar-talks-with-uk-falter

Shortly afterwards – in the spring of 2025, according the latest plan – prospective UK visitors to the Schengen area will have to apply online for permission to enter.

Source: https://www.independent.co.uk/travel/news-and-advice/brexit-border-etias-dover-eurostar-b2130495.html