One of Europe’s largest salmon farmers has been accused of attacking the civil rights of environmental campaigners by asking for sweeping restrictions on their freedom to investigate alleged animal rights breaches.

The Faroese company Bakkafrost, which produces about 20% of the UK’s farmed salmon, has asked a judge to consider banning the campaigner Don Staniford from going within 15 metres of any of its fish farms, boats and barges.

The company is seeking an interdict, or injunction, that would extend to anyone acting with Staniford, or guided by him, from approaching, entering or boarding any of Bakkafrost’s more than 200 salmon farms, ships, factories, docks, hatcheries and offices – including its head office in Edinburgh.

Civil rights groups argue that Bakkafrost’s legal action amounts to an attempt to shut down legitimate investigations in the public interest, using a tactic known as a strategic lawsuits against public participation, or Slapp.

Staniford, one of the UK’s most prominent fish farm campaigners, has already been ordered to stay away from fish farms and land bases in Scotland owned by the Norwegian multinational Mowi and by Scottish Sea Farms.

Staniford has documented conditions in Scottish salmon farms. Photograph: Colin McPherson

Staniford, who is based in north-west England and known to his supporters as the “kayak vigilante”, boards salmon farms to look for any evidence of disease or parasite infestations on fish, or any evidence of illegal chemical discharges, at times with documentary film-makers and journalists.

All three firms say they uphold the highest legal and welfare standards on their farms.

Bakkafrost’s legal action, being heard at Dunoon sheriff court near Glasgow, is trying to establish an even broader restriction than its competitors by asking for the 15-metre exclusion zone around all its water-borne assets. Breaching that interdict would be a contempt of court, exposing campaigners to the risk of imprisonment.

Mowi tried and failed to impose a similar exclusion area against Staniford but that restriction was thrown out on appeal. Staniford said Mowi is pursuing him for £123,000 in court costs and legal costs – a bill he is unable to pay.

Nik Williams, a policy officer with the Index on Censorship and a co-chair of the UK Anti-Slapp coalition, said sweeping bans of this kind, particularly if the interdict appeared to include anyone associated with Staniford, had a chilling effect on public debate.

He said: “Anywhere there are legal constraints like this, people will step back scrutinising these incredibly influential industries”, adding it was “quite concerning” that Bakkafrost was seeking a 15-metre exclusion area despite knowing that Mowi’s application to do so had failed.

Bakkafrost wants its “extended interdict” to include Staniford “by himself or by his agents, employees, or servants, or by anyone acting on his behalf or under his instructions, or procurement”.

In the first day of the hearing, Staniford’s lawyer, Nicole Hogg, told the sheriff, Laura Mundell, the judge presiding over the case, that Bakkafrost wanted sweeping restrictions on him without specifying why they were needed.

Staniford is known to his supporters as the ‘kayak vigilante’ Photograph: Colin McPherson

She said it had failed to produce evidence that it owned or leased the land-based properties it wanted to protect, or why an exclusion zone was necessary at sea. “It is not sufficiently precise,” she told Mundell.

Ruairidh Leishman, acting for Bakkafrost, said the 15-metre zone was useful because it set a precise boundary for the court, but it was asking for it to be imposed only if the judge believed it necessary.

He said the case it had against Staniford would be disclosed at a later hearing, but this was not an attack on his freedom of expression.

Even though Staniford had voluntarily agreed not to enter its properties in December 2024 while its application was being heard, he had continued to make highly critical comments about Bakkafrost. “This a case about property rights and not freedom of expression,” Leishman told the court.

The case is due to continue at a later date.