Despite a knockback last week, moves are afoot in the UK to stop the super-rich from using their wealth to silence media investigations.

Minister of state for security Tom Tugendhat refused an amendment to an proposed economic crime bill that would have given judges the power to dismiss Slapps – ‘strategic lawsuits against public participation’.

Senior journalists and editors have got together this week, writing to justice secretary, Dominic Raab urging action to stop “oligarchs and kleptocrats” from using their money to take advantage of Britain’s legal system to intimidate and silence investigative journalists through such lawsuits.

More than 70 newspaper editors, publishers and media lawyers – among them the editors of The Times, the Guardian, the Sun, Financial Times, Daily Mail and Bloomberg – wrote demanding that the government take urgent action to address Slapps.

The “endemic” use of Slapps was hampering not only investigative journalism but also “law enforcement’s ability to investigate wrongdoing promptly and effectively”.

Editors claimed recent examples of Slapps included Roman Abramovich suing the journalist Catherine Belton over her book Putin’s People, and the Kazakh mining firm ENRC suing the journalist Tom Burgis over a book about “dirty money”. These cases were “just the most visible manifestation of a much broader problem which has affected newspapers across Fleet Street and the wider UK media industry for many years”.

Tugendhat agreed the law needed to be reformed but said an amendment to the economic crime bill was not appropriate. The justice ministry was working on a piece of “anti-Slapps legislation” that addressed the whole problem, he said.

The UK had been identified as the leading international source for legal threats against journalists investigating financial crime and corruption in research two years ago, according to deputy director of the Foreign Policy Centre Susan Coughtrie, who is co-chair of the UK Anti-Slapp Coalition.

“Adopting a UK anti-Slapp law would protect those trying to uncover wrongdoing – in any form – and ensure the free flow of information about matters of public interest, essential to any healthy democracy,” she said.