Last year, the activist was stopped at the Channel Tunnel terminal in Folkestone under the Counter Terrorism and Border Security Act. Alleging that Robinson was being evasive when questioned, carrying a large quantity of cash, and driving a car not registered under his name, officers ordered him to provide the PIN to his telephone. Robinson refused. This, the prosecution argued, constituted an offence under Schedule 7 of the Terrorism Act. The defence suggested it was an example of police overreach, and “a fishing expedition”. Former MP George Galloway was stopped by police at Gatwick last month under the same legislation after visiting Moscow.

District Judge Sam Goozee said: “I cannot put out of my mind that it was actually what you stood for and your beliefs that acted as the principal reason for the stop.” Goozee also noted that Robinson’s political beliefs were a “protected characteristic” under the Equality Act 2010. The English Defence League founder, whose legal costs were reportedly covered by tech boss Elon Musk, told reporters it was “a powerful judgment now that says it how it was — I was targeted because of my political beliefs.”

Why, then, do police have such sweeping powers, and have they abused them? Officers are entitled to stop any person entering or leaving the UK “to determine whether they may be involved or concerned in the commission, preparation or instigation of acts of terrorism”. Performing these duties in the Nineties, before the Good Friday Agreement, I know how bitterly contested such powers are: Sinn Fein and other Republican groups routinely challenged police decision-making when their activists were detained for questioning. A grey area exists between terrorism and those who may support and facilitate terrorist acts. As Goozee said of Robinson’s case, “it may be impossible to draw a line between your political beliefs, philosophical beliefs and terrorism, as there can be a clear overlap.”

This case, ostensibly, turned on the clearly intrusive power to demand people surrender their electronic devices for examination by police. Yet by invoking the term “protected characteristics”, in this instance political beliefs, the judge has opened a can of worms. Officers will be required to reconsider the grounds for stopping “subjects of interest” based on political affiliations. Robinson has no known links to terrorists; clearly, officers chose to interpret his activities as encompassing the grey area of potential extremism. Their evidence, however, was described as vague, which suggests the court viewed the stop as opportunistic. This has all the makings of a potential “stated case”, one marking a watershed moment in the way the Terrorism Act is applied to travellers entering and leaving the UK.

Also watching the case with interest will be the Office of Security and Counter-Terrorism, the Home Office department which oversees such matters. Have officers been given adequate guidance around who, and for what reasons, should be stopped under the Act? The department issued guidance earlier this year suggesting that concerns over immigration were “cultural nationalism” and a potential precursor to terrorism. Critics might suggest politicians and civil servants should be mindful of which views they consider to meet the threshold of extremism. As things stand, the courts have taken a dim view of the way officers have used — or misused — the Act in dealing with Robinson.