Greenpeace’s boss could be jailed for two years, after the owner of a rig that eco-activists blocked from drilling for new oil wells pursued legal action against him.

John Sauven, the executive director of Greenpeace, whose HQ is at Canonbury Villas, attended a hearing at Edinburgh's Court of Session today, which saw Transocean seek to hit the non-governmental organisation with unlimited fines for contempt of court.

The Greenpeace ship Arctic Sunrise blocked the Transocean rig - which BP was paying £140,000 a day to use - as it was en route to the Vorlich oil field in the North Sea to drill for new wells in June, forcing it to do a u-turn and head back to shore.

Greenpeace stands accused of breaching an interim interdict secured by Transocean - with BP's consent - because it continued its protest - which eventually lasted for 12 days and saw activists board the rig.

Lawyers for Greenpeace argued it was necessary to disrupt the BP rig to prevent the multi-national oil and gas giant from making the climate emergency worse by extracting 30 million barrels of oil.

Scientists have warned that to limit global warming to 1.5°C we must not burn the oil and gas that has already been extracted.

Greenpeace UK executive director John Sauven branded the legal action an attempt to stifle climate campaigners through legal action.

He said: "Six months after our rig action ended, and after getting a permanent interdict against Greenpeace, BP's rig operator Transocean is desperately doing everything it can to scare us off. But we will not be silenced. We will stand up proudly in court to defend our peaceful protest.

"Stopping BP's rig was our moral duty when faced with oil giants fuelling the climate emergency, threatening the safety of our planet and putting lives at risk."

A spokesperson for BP denied the legal action had anything to do with them and said they did not wish to comment.

Transocean was approached for comment but has not responded. Their lawyer John Barne QC asked the court to make an example of Greenpeace, and warned of soft penalties for climate groups. He said: "If in terms of penalty the court gives a message that this is okay when there are other organisations out there that are less well-trained and less safe than Greenpeace, it is important that people understand that the court can give protection and that that protection should be obeyed."

Judge Lady Wolffe will deliver a verdict on March 23.

In a separate legal case, Greenpeace has been granted permission to judicially review BP's drilling permit for the Vorlich oil field east of Aberdeen. Greenpeace argues that the permit is unlawful because there was no proper public consultation.