At the Immigration and Asylum Chamber

When Trenton Oldfield disrupted the Oxford and Cambridge Boat Race last year, he knew his protest against ‘unjust inequalities in British society’ was illegal, but couldn't have foreseen the full extent of its fallout. He was initially charged with disorderly behaviour, but the Crown Prosecution Service – eager to deter protesters in the run-up to the Olympics – upgraded the charge to public nuisance. Sentencing Oldfield to six months in prison, the judge called his actions 'disproportionate', a word that could be applied to the decision itself.

Having served seven weeks and paid the crown's costs, Oldfield received another blow: earlier this year the Home Office rejected his spousal visa application. An Australian citizen, he has lived in the UK since 2001, as a ‘highly skilled migrant’; he had no previous convictions and his sentence didn’t lead to automatic deportation; the refusal came days before his British wife gave birth to their first child. The Home Office said that Oldfield's presence in the country was 'not conducive to the public good'.

At first Oldfield and his wife, Deepa Naik, thought it was a technical glitch. The UK Border Agency – as it’s still known eight months after Theresa May announced its dismantling – has a backlog of hundreds of thousands of immigration cases, going back a decade. One day border checks are suspended at a number of ports; the next family immigration laws are tightened up with the introduction of a minimum earnings requirement. After a Bolivian who overstayed his student visa was granted leave to remain as an unmarried partner of a British citizen, May wrongly said it was because he had a pet cat and called for the UK to withdraw from the European Convention on Human Rights.

Article 8 of the convention, which guarantees respect for private and family life, gave Oldfield and his supporters hope that his appeal against the decision might be successful. They argued that deporting him would infringe the rights of his wife and their five-month-old daughter. The appeal was heard at the Immigration and Asylum Chamber of the First-tier Tribunal on Monday. Several dozen people gathered outside the building in north London, some brandishing banners, and cheered Oldfield when he arrived with his family. The allocated courtroom turned out to be surprisingly small. ‘Seven or eight of you may be able to get in,’ the clerk said. ‘If you are going to wait here keep clear of the fire doors.’

While Oldfield was being briefed by his lawyers, Naik recalled the visa saga that had been going on for months: the Home Office had repeatedly failed to submit necessary documents. One of the supporters talked about East London’s radical movements. Another told a story about the wetsuit Oldfield wore when he jumped into the Thames, now in the Bishopsgate Institute archives. There were other people waiting there too. A Nigerian couple weren't sure if the minimum income threshold should apply to them: they’d submitted their application before the new guidelines came into effect but some of the paperwork had been lost. A wire journalist with a place in the courtroom kept us up to date with the proceedings.

Stephanie Harrison QC, representing Oldfield, said that the protest ‘was not of sufficient gravity and seriousness’ to justify deportation. Oldfield broke down in tears when he spoke of looking after his wife’s dying father shortly before the protest. He said that Naik, who is of Indian extraction, couldn't possibly move to Australia, ‘a particularly racist country’.

More than 250 staff and students at Oxford and Cambridge signed a letter to the tribunal, saying Oldfield shouldn’t lose his family for interrupting an amateur sporting event for half an hour. At least 100 people wrote character references for Oldfield; several came forward as witnesses. Danny Dorling, a professor of geography at Oxford whose areas of study include inequality among population subgroups, told me before giving his statement that if Oldfield’s protest was detrimental to society, so was his own research. Jeremy Till, the head of Central Saint Martins, praised Oldfield and Naik’s project This Is not a Gateway, and said that their publications and events had made a valuable contribution to the debate on contemporary urbanism.

Summing up, the judge said: ‘It would be my intention to allow your appeal.’ The decision could take up to ten days to become official, but the lawyers said indications of this kind were very rare and they had reason to believe it was a win. Oldfield came out looking drained, apologising for having to 'zip out of here' to take his family home. Before leaving, he said that the media should focus not on him, but on things happening ‘every single day in this building’.

The attempt to kick Oldfield out of Britain has been called 'vindictive', but the reality seems more prosaic: the system lurches from one extreme measure to another, struggling with resources and remaining not fit for purpose. Leaving the tribunal, looking back at the crowd of people waiting for their cases to be called, I couldn't help thinking that the way immigration is managed in this country is not conducive to the public good.