The editor, Alan Rusbridger, said: "The media laws in this country increasingly place newspapers in a Kafkaesque world in which we cannot tell the public anything about information which is being suppressed, nor the proceedings which suppress it. It is doubly menacing when those restraints include the reporting of parliament itself."

The right to report parliament was the subject of many struggles in the 18th century, with the MP and journalist John Wilkes fighting every authority – up to the king – over the right to keep the public informed. After Wilkes's battle, wrote the historian Robert Hargreaves, "it gradually became accepted that the public had a constitutional right to know what their elected representatives were up to".

The only fact the Guardian can report is that the case involves the London solicitors Carter-Ruck, who specialise in suing the media for clients, who include individuals or global corporations.