The stop matters because Schedule 3 is not an ordinary arrest power and it does not by itself mean a person has been charged with terrorism or espionage. It is a border-examination power that allows an examining officer to question a person at a port or border area to decide whether the person appears to have been engaged in "hostile activity", a statutory term tied to acts carried out for, on behalf of, or in the interests of a state other than the UK, according to the legislation and the Home Office code of practice.
Sky News reported that Yaxley-Lennon said on X that he had been held for "the best part of three hours" and that his phones had been seized. The Independent reported a Met statement saying officers stopped a man in his 40s at around 17:00 on Saturday, June 13, after his return from Russia via Turkey; the statement said he was interviewed, his communication devices were seized, and he was later released.
The Guardian and the Financial Times also reported that the stop used the 2019 Act's border powers and that officers seized communication devices. The Financial Times reported that the stop followed Yaxley-Lennon's return from Russia and involved questioning at Heathrow.
Under Schedule 3, an examining officer may question a person to determine whether the person appears to be or have been engaged in hostile activity. The statute also says the power may be exercised "whether or not there are grounds for suspecting" that the person has been engaged in hostile activity, which is why the power is legally sensitive and why a stop should not be reported as a finding of wrongdoing.
The Home Office code of practice says the power covers stops, questioning, searches and detention at ports and the Northern Ireland border area, and says officers must explain at the start of an examination that the person is being examined under Schedule 3 and that the officer has a power to detain for the examination. The same code defines the purpose as deciding whether the person appears to have been engaged in hostile activity, not proving a criminal charge at the border.
The statute sets time limits and evidence rules. A person questioned under Schedule 3 may not be questioned for more than one hour unless detained under the schedule, and a person detained under that paragraph must be released no later than the end of six hours unless held under another legal power. It also restricts the use of oral answers in criminal proceedings, subject to listed exceptions, according to Schedule 3.