An injunction preventing a former member of the SAS from publishing a book about his role in a counter-terrorism operation has been extended after an application by the Ministry of Defence.

The block on publication of the book in the UK will continue until the conclusion of a government legal action against the soldier, who is known only by the pseudonym Christian Craighead.

Craighead received the Conspicuous Gallantry Cross – a medal one level down from the Victoria Cross – for his involvement in an incident after an al-Shabaab attack in the Kenyan capital of Nairobi in 2019 in which 21 people died.

Craighead claims to have saved more than 700 people from a hotel complex in Nairobi after a group of armed militants launched an assault.

The MoD claims that Craighead’s book contains an alleged breach of a confidentiality contract that he had freely signed on joining the UK’s special forces.

An interim injunction was issued this month, with government barristers returning to the high court on Thursday to ask for it to be extended until the legal claim is resolved.

Oliver Sanders KC, for the MoD, told the court in London the claim that Craighead had breached the contract was “straightforward and really unarguable”.

The book has been published in the US but Sanders said that this was not relevant because “the only reason it is available overseas is through the defendant’s own wrongdoing”.

Craighead did not appear in court and was not represented.

In a ruling extending the injunction, Mr Justice Saini said Craighead “willingly entered into” the contractual agreement and was “clearly and consistently told by his superiors” that he would not be permitted to publish the book.

The judge said he believed the MoD had an “overwhelming case for an injunction” and that Craighead appeared to have committed a “flagrant breach” of the contract, which he did “having his eyes open to the potential consequences”.

Craighead lost a legal challenge against the MoD in 2023 after it refused to allow the book’s publication, citing national security concerns.

Craighead joined the armed forces in 1992 and served in the special forces from 2006 to 2020.

The court was previously told that when joining the special forces Craighead signed an agreement preventing him from disclosing information about his time in the SAS.

The confidentiality contract stated that Craighead would give a “solemn undertaking binding me for the rest of my life” not to disclose information relating to his special forces service without “express prior authority in writing” from the MoD, which has not been given in relation to the book.

Sanders said: “If he had not signed the contract, he would not have served in the UK special forces. He would not have been in Nairobi; he would not have had the training, the equipment, the weapons, the support. While he does not like it, this is what he agreed, and as a matter of contract law it is very, very straightforward.”