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Court finds that the Home Office’s imposition of a GPS tag was unlawful for over a year in the first case of its kind


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On 11 March 2024, the President and Vice-President of the Upper Tribunal (Immigration and Asylum Chamber) handed down their decision in R (Mark Nelson) v Secretary of State for the Home Department (JR-2023-001472), the first challenge to the Home Secretary’s policy of requiring people on immigration bail to be monitored 24/7 by GPS devices. You can read the full judgment here.

The applicant, Mark Nelson – a father of five, car mechanic and UK resident of 24 years – argued the imposition of a GPS tag was an unlawful interference with his article 8 rights under the European Convention on Human Rights. Mr Nelson also argued that requiring him to wear a broken GPS tag for a period of around six months was outside the Home Secretary’s statutory powers and that to force him to do so was an exercise of arbitrary and undemocratic power.

This article will summarise the key findings of this judgment. It will also end with some practical steps practitioners can take if conducting similar judicial review challenges. 


Mr Nelson is subject to deportation proceedings. In May 2022, he was released from detention and fitted with a GPS tag as a condition of immigration bail pursuant to the Home Secretary’s duty under paragraph 2, Schedule 10, Immigration Act 2016.

By way of background, GPS tags collect vast amounts of data including sensitive and personal data and use this data for spurious and non-transparent purposes. Wearers must also keep the tag sufficiently charged at all times (which takes several hours of charging per day) otherwise they may be held in breach of their bail conditions. This can have serious consequences such as being detained. 

Evidence was provided to the court that being subject to 24/7 surveillance and the stress of needing to keep the tag charged had significantly impacted Mr Nelson’s mental health and everyday life. It curtailed Mr Nelson’s willingness to be seen in public for fear of stigmatisation, discrimination and ostracisation. It also caused the onset of multiple mental health conditions he had not experienced previously.   

At the date of the hearing, Mr Nelson had been wearing his GPS tag for 18 months, with the tag having been broken for six of those months. Despite notifying the Home Secretary that he believed his tag was not be sending GPS signal as early as December 2022, the Home Secretary took no real steps to remedy the issue and denied that the tag was not working.

During the hearing, Mr Nelson argued that his compliance with immigration enforcement could be managed by less intrusive means and it was therefore not proportionate to impose a GPS tag on him. This was argued, among other reasons, because Mr Nelson had been held to be fully compliant with all his immigration bail conditions throughout, even during the period he knew his tag not to be working.

Before moving onto the decision, it is worth briefly highlighting that, for individuals who also have Article 8 immigration claims, one of the reasons the Home Office can access GPS trail data according to his Immigration Bail policy is to assess the credibility of such a claim. The lawfulness of this was not ultimately decided upon in this case since the Home Secretary confirmed he had not accessed Mr Nelson’s GPS data for this purpose. However, the Home Secretary did confirm the circumstances he might do this is:

for example, if the claim was that the individual has formed a relationship with a new partner and that partner has children, one of whom has severe medical needs. Individual submits that he/she has a crucial part to play in the child’s medical regime and sleeps at the hospital 3 times per week with the child whilst the partner cares for the other children. GPS trail data would confirm this without the need to contact the hospital administration staff.

[paragraph 55]

The possible access and reliance on the GPS trail data by the Home Secretary in these circumstances is concerning given the reports of systemic inaccuracy of the GPS data itself (discussed further below).


On the first day of the trial, the Home Secretary conceded that Mr Nelson’s GPS tag had been broken for about six months (despite Mr Nelson raising this concern almost a year prior).

The Tribunal held that forcing Mr Nelson to wear the tag during the period in which it was broken was a disproportionate interference with his rights under article 8 of the Convention. Requiring Mr Nelson to wear a tag while it broken was ‘essentially pointlessas the Home Secretary knew it was not working since imposing it could not fulfil the ‘legitimate aims’ of the legislation [paragraph 65]. The tribunal also found this to be a public law error [paragraph 66].

The Home Secretary further conceded that he had failed to conduct lawful reviews on the proportionality of the decision to maintain the GPS tag until July 2023 (i.e. for over year after Mr Nelson had been first tagged). The Tribunal held these failures to mean the Home Secretary’s tagging of Mr Nelson during this period was not ‘in accordance with the law’ [paragraphs 57-59]. The Tribunal held that the requirement to conduct regular reviews were an ‘integral part of the legal framework’ since the Home Secretary can only continue to tag someone if it is not a breach of their human rights or it is impractical to do so. Only through regular reviews can this assessment be maintained lawfully [paragraph 64].

Ultimately, however, the tribunal held that the ongoing decision to require Mr Nelson to wear a GPS tag as a condition of immigration bail at the time of the hearing was proportionate [paragraph 76]. The tribunal noted that it was finely balanced, but “the importance of maintaining a prompt and effective system of enforcement of immigration control together with the risks of absconding and the potential proximity of the end of the applicant’s appeal proceedings all attract significant weight in the balancing exercise” [paragraph 77]. 

Since this is the first case assessing the proportionality of this intrusive technology, given the large number of people this issue affects and given the ongoing impact of the tag on Mr Nelson, Mr Nelson intends to apply for permission to appeal to the Court of Appeal on this point.

Concluding remarks

While Mr Nelson is still required to wear the tag, this judgment has significant consequences for the Home Secretary’s policy of GPS tagging migrants. Prior to this case, the Home Secretary was running this highly intrusive scheme without any judicial oversight. This is because the Home Secretary was settling the majority of these cases via out-of-court settlements before any hearing would take place. You can read more about the background of these other legal challenges here.

There is evidence that the Home Secretary has been failing to conduct lawful reviews in hundreds of other cases, and until this decision, this has been without consequence. Likewise, there is significant evidence that Mr Nelson’s broken tag is not an isolated incident. There are reports of systemic failures with the GPS tagging technology on a scheme-wide basis. This means there are likely hundreds, if not thousands, of people who are currently being tagged in breach of their article 8 rights and for no lawful reason.

These findings follow just two weeks after a decision by the Information Commissioner’s Office (the ‘ICO’ – the UK’s data protection regulator) on the Home Office’s use of people’s data under its pilot GPS tagging scheme. The ICO issued a formal warning that ‘any future processing by the Home Office on the same basis will be in breach of data protection law and will attract enforcement action.’ 

The impact of these decisions together is that the Home Office will no longer be able to impose this intrusive form of surveillance on people without regard for whether the technology is working of whether it is – and continues to – absolutely necessary at all times.

Further, although raised by Mr Nelson, the Tribunal did not make a formal decision on the lawfulness of any possible use of automated decision-making that may have been used in decisions to maintain Mr Nelson’s tag. Nor did they decide on the evidence provided by Mr Nelson and Privacy International that the tags do not, or are not capable of, accurately recording individuals’ locational data. Cases that focus on these issues will prove to be determinative in the coming years as the Home Office continues to experiment with new forms of technology on migrant populations.

Practical advice

There are some key practical steps practitioners conducting similar judicial reviews may be advised to take:

  • Request disclosure of the GPS tag’s trail data. This will reveal if there are key periods where the tag is not collecting data. You can then also cross-check some of the locational data against your client’s memory of their movements. If there are significant discrepancies, consider preparing a witness statement highlighting these inaccuracies with the data.
  • Request disclosure of whether any ‘automated business rules’ have been used in the preparation of any reviews of the electronic monitoring condition. The lawfulness of this technology has not yet been assessed and raises serious privacy and data protection concerns.
  • If your client also has an article 8 immigration claim, make sure your client also takes a personal record of their movements that may be relevant to an article 8 claim. This is so that any claims made by the Home Secretary based on the (potentially inaccurate) GPS trail data can be verified or rebuffed.
  • If – as in the example provided by the Home Secretary above – the tag is collecting data that is sensitive or related to children, consider raising a complaint with the Information Commissioner’s Office.
  • Ensure the Home Secretary has conducted a review of the electronic monitoring condition every three months or on the receipt of representations. Otherwise, the continued wearing of the tag may be unlawful.

Mr Nelson is represented by Katie Schwarzmann of Wilson Solicitors LLP, Donnchadh Greene of Doughty Street Chambers and Sarah Hannett KC of Matrix Chambers. Evidence relating to the functionality of GPS tags was provided by Privacy International.  

Wilson Solicitors LLP represents a number of individuals challenging the Home Office’s imposition of GPS tags on them. 

You can listen to a podcast on this case where Mr Nelson and his solicitor, Katie Schwarzmann, were interviewed by Privacy International here.

This article was co-written with Donnchadh Greene of Doughty Street Chambers.

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Katie Schwarzmann

Katie joined Wilsons in May 2022 as a solicitor in the Public Law & Human Rights department. Katie represents asylum seekers, victims of trafficking and other marginalised clients to assert their rights against the government by way of judicial review and civil claims for compensation.