All passengers, including British and Irish nationals, on scheduled services into UK ports from outside of the Common Travel Area (CTA) are subject to checks on arrival. British and Irish nationals arriving in the UK from within the CTA do not pass through immigration controls, though may be included in intelligence-led border security checks. This is in line with the existing CTA arrangements between the UK, Ireland and the Crown Dependencies and the UK’s legal framework as set out in the Immigration Act 1971. The Government has been clear that it intends to maintain the CTA. The introduction of routine immigration controls would require legislative change.