The Biden administration is seeking a 45-day delay in a court proceeding in which it has been asked by a US judge whether it believes Crown Prince Mohammed bin Salman should be granted sovereign immunity in a case involving the murder of Washington Post columnist Jamal Khashoggi. Representatives from the US justice department said in a legal notice filed on Friday that the department was seeking the extension after Saudi Arabia announced in a press release last week that Prince Mohammed had been named prime minister. Critics of the Saudi government said they believed the new designation was a manoeuvre designed to try to establish sovereign immunity protection for the 37-year-old prince, who is facing a civil case in the US for his alleged role in the murder of Khashoggi. The legal case, which is being heard in a district court in Washington DC, has been filed against Prince Mohammed by Hatice Cengiz, Khashoggi’s fiancee, and Dawn, a pro-democracy group founded by the journalist before he was killed. The case has put the Biden administration in a legal and diplomatic bind. The US president entered the White House promising to make the crown prince accountable for Khashoggi’s murder and to make him a “pariah”. But Biden has largely abandoned that pledge in favour of pursuing other political and foreign policy objectives. In a trip to Jeddah this summer, the president fist-bumped the crown prince even after his own administration released a declassified intelligence briefing last year that concluded Prince Mohammed had likely ordered the Khashoggi killing. Prince Mohammed has said he has taken responsibility for the murder but that he did not order the killing. The administration is not formally a party to the case, but was invited to weigh in on the matter. It had been given until 3 October by a judge hearing the Khashoggi case to respond to a series of legal questions about whether Prince Mohammed should be granted legal immunity, which traditionally is granted to a state’s ruler, like a prime minister, president or king. In its two-page filing on Friday, the Biden administration acknowledged it needed more time after already being granted an extension to settle the issue because of Prince Mohammed’s recent elevation to the role of prime minister. “In light of these changed circumstances, the United States requests a second extension of time of 45 days to prepare its response to the Court’s invitation,” the administration said in a notice to the court. “The United States appreciates the Court’s patience and consideration in this matter.” Legal experts who have studied the issue say they believe Cengiz’s legal team will likely challenge any legal argument that calls for Prince Mohammed to be granted immunity. Among other issues, they will likely argue that King Salman’s designation was solely designed for Prince Mohammed to evade justice. That is because, in announcing the change – an exception to Saudi law that calls for the king to also serve as prime minister – it is stated that King Salman will still act as prime minister in meetings in which he is present. Human-rights lawyers have also argued against giving sovereign immunity protection precedence over other principles human rights principles. Agnès Callamard, the secretary general of Amnesty International, said there were “far greater values at stake” than the immunity of a “possible sovereign that has proven repeatedly that he is prepared to violate the sovereignty of other states and international law”. “The protection of the right to life, the prohibition of torture and enforced disappearance, international peace, the use of force on the territory of another state, principles of international justice and the protection of fundamental human rights should trump concerns of sovereign immunity,” Callamard said. Sarah Leah Whitson, a lawyer and executive director of Dawn said the best thing the US government could do would be to refuse to weigh in on the matter. Any such decision would likely be seen as a sign to the court that the administration did not believe it had an interest in the case. “MBS’s [Mohammed bin Salman’s] ploy to secure immunity by designating himself as PM should be rejected as an abuse of sovereign immunity. To allow tyrants to dodge prosecution for war crimes and grave abuses by title-washing will eviscerate universal jurisdiction laws all over the world,” she said. Experts have also cautioned that much more is at stake for Prince Mohammed than the civil case in Washington. If a US judge were to determine that the crown prince should be granted sovereign immunity, it would likely assure the crown prince that he was no longer facing legal threats or the threat of possible arrest when he travels outside the kingdom. If a judge determines that Prince Mohammed ought not to be granted sovereign immunity – either because he is not yet fully ruler of the kingdom, or because his alleged wrongdoing was too grave – it would conversely send a stark message that the crown prince could face more legal trouble. The decision in the first instance will be made by Judge John Bates, who was appointed to the bench in 2001 by then-president, George W Bush. Bates has previously received media attention as a Republican-appointed federal judge who ruled against the Trump administration in 2018 after the White House sought to end an Obama-era programme known as Daca, which was designed to protect immigrants who arrived in the US as children. Bates called the Trump administration’s reasoning in the case “arbitrary” and said it had not given sufficient explanation of why the programme should be considered unlawful.