The prime minister confirmed the discussions would go ahead at the G20 summit in Argentina – where the prince is likely to be shunned by the likes of Angela Merkel and Emmanuel Macron.

The US Congress has demanded an investigation into whether bin Salman was behind Khashoggi’s murder, in the Saudi consulate in Turkey on 2 October.

Furthermore, an estimated 85,000 children under the age of five have died in Yemen from extreme hunger or disease since war broke out between a Saudi-led coalition and Iran-backed rebels.

Up to 14 million people are at risk of famine, blamed largely on the stranglehold the Saudis have imposed on the Yemeni economy.

Ms May has rebuffed widespread calls for the UK to end arms sales to the kingdom, insisting there are rigorous checks to ensure they are not used in any human rights abuses.

Jamal Khashoggi death: key figures Show all 7 1 /7 Jamal Khashoggi death: key figures Jamal Khashoggi death: key figures Jamal Khashoggi Washington Post journalist who was critical of the Saudi regime and the young Crown Prince Mohammed bin Salman, he was murdered on 2 October in the Saudi Arabian consulate in Istanbul AFP Jamal Khashoggi death: key figures Saudi Crown Prince Mohammed bin Salman Heir to the Saudi throne, Mohammed bin Salman has been implicated in the murder, with US officials claiming that he must have known of the plot AFP/Getty Jamal Khashoggi death: key figures 15 man hit squad Turkish police suspect these 15 men of being involved in the murder of Jamal Khashoggi, issued 10 October, 8 days after the journalist disappeared EPA Jamal Khashoggi death: key figures Saud al-Qahtani Aide to Crown Prince Mohammed bin Salman, Saud al-Qahtani is claimed to have ordered Khashoggi's murder Saud Al-Qahtani/Twitter Jamal Khashoggi death: key figures Maher Abdulaziz Mutreb A former diplomat who often travelled with the Crown Prince, Mutreb was initially claimed to be the leader of the hit squad and is pictured here entering the Saudi consulate on the day of the murder AP Jamal Khashoggi death: key figures Mustafa al-Madani First implicated in the 15 CCTV photos released by the Turkish police, al-Madani was later found to have been used as a body double for Khashoggi, leaving the Saudi consulate dressed in his clothes on the day the journalist was killed CNN Jamal Khashoggi death: key figures Salah bin Jamal Khashoggi (L) Son of the murdered journalist met with Crown Prince Mohammed bin Salman on 23 October EPA

“I’m intending to speak with the crown prince of Saudi Arabia,” she told reporters ahead of landing in Argentina.

“The message that I will give will be the message that we have consistently given on this issue, but also on the issue of Yemen.

“In relation to Mr Khashoggi, we want to see a full and transparent investigation in relation to what happened and those responsible held to account

“On the issue of Yemen, we continue to be deeply concerned about the humanitarian situation. We will be encouraging all the parties to work for a political solution.”