More than £1m has been donated to Greenpeace UK’s Stop Shell appeal, which was launched in response to a major lawsuit filed by Shell against the environmental non-governmental organisation.

The legal action was filed by Shell after Greenpeace campaigners occupied a moving oil platform for 13 days in January last year to protest against climate damage caused by the oil company.

Four campaigners boarded the platform just north of the Canary Islands while it was being transported to the Shetland Islands, according to reports in The Guardian.

At the time, Shell sought and received injunctions from the court, which the oil company said was to “prevent an escalation of these protests” and required a legal claim against Greenpeace.

Greenpeace said Shell’s claim was seeking $1m (£789,000) in damages, but said legal costs incurred were “likely to run into millions”. Shell did not confirm how much it was seeking in damages.

Greenpeace said the lawsuit is the “one of the biggest legal threats any Greenpeace organisation has faced in its 53-year history”, saying that the case was “intended to intimidate the group into silence and drain its resources”.

But a spokesperson for Shell said the case was about “preventing the kind of dangerous and unlawful protest at sea that puts lives in danger, including the protesters themselves”.

Greenpeace’s Stop Shell appeal, which it launched in November in response to the lawsuit, has raised more than £1m, receiving nearly 25,000 donations in just nine months. 

The appeal has received support from several celebrities, including the actor, comedian and screenwriter Simon Pegg, the author, broadcaster and writer Stephen Fry, and the actors Emma Thompson and Benedict Cumberbatch.

The campaign has also involved social media spoof videos and celebrity partnerships, including a video from comedian Joe Lycett in which he pretended to sue the singer Harry Styles for a KitKat, which resulted in more than £70,000 raised in T-shirt sales.

Greenpeace also delivered the “world’s tiniest violin” to Shell’s chief executive, Wael Sawan, at its office in London, as part of the campaign.

The lawsuit has been labelled by some as a strategic litigation against public participation, with the UK Anti-Slapp Coalition having issued a statement in support of Greenpeace.

Philip Evans, campaigner at Greenpeace UK, said: “Shell’s attempt to intimidate us is only making us stronger. Ordinary people have had enough of watching Shell make billions in profit from a commodity that’s driving energy bills up and fueling climate disasters around the world. Shell might have deep pockets, but the determination of our supporters runs deeper.

“Those in power are doing nothing to hold the fossil fuel giants to account. The new Labour government should place bold new polluter taxes on oil companies to support the communities hit hardest by the climate crisis at home and abroad.”

The spokesperson for Shell said: “This is not, and never has been, about preventing Greenpeace’s freedom of expression. The right to protest is fundamental and Shell respects this absolutely, but it must be done safely and legally.

“At the time the injunctions were granted, the judge said protestors were ‘putting their lives and, indirectly, the lives of the crew at risk’. He was also clear that Greenpeace could still protest from a safe distance and that their human rights were not infringed.”