A Number 10 readout of that call on Feb 11, before Russia’s full invasion of Ukraine, said the pair “welcomed defence and security collaboration between the UK and Saudi Arabia”.

There was also a line suggesting a meeting could soon be arranged, reading: “The Prime Minister and crown prince looked forward to meeting in person at the earliest opportunity.”

Tory MPs on Wednesday night suggested that Mr Johnson could use his connections with the Saudis to solve the Biden impasse and convince the country to release oil reserves.

Andrew Murrison, the Tory MP who served as Mr Johnson’s Middle East minister until Feb 2020, said: “The energy crunch means that jurisdictions are going to have to look further afield for continuity of supply, which may mean some compromises. But we have to judge very often the lesser of a number of evils.

“The UK has always maintained a positive and constructive relationship with Saudi Arabia based on dialogue. I’m sure that will be useful in the current context.”

Steve Baker, a Tory MP who holds a senior position in the Net Zero Scrutiny Group, said: “Boris has come into his own during this crisis.

“Now would be just the moment for him to help deliver more flows of oil and gas from Saudi Arabia so we can shut down [Russian President Vladimir] Putin’s war machine sooner.”

‘Partner’ for the UK

The Prime Minister’s spokesman said earlier on Wednesday that Mr Johnson continued to see Saudi Arabia as a “partner” for the UK.

US officials told the Wall Street Journal that the White House tried to reach the crown prince and the UAE’s Sheikh Mohammed bin Zayed al Nahyan in recent weeks, but both declined.

“There was some expectation of a phone call, but it didn’t happen,” a US official told the paper. “It was part of turning on the spigot [of Saudi oil].”

The relationship between Riyadh and Washington is under stress, with sticking points on the war in Yemen, the resurrected Iranian nuclear deal and responsibility for the killing of Mr Khashoggi.

Mr Khashoggi was murdered and dismembered by a Saudi government hit squad in the kingdom’s Istanbul consulate in Dec 2018. The CIA concluded that the killing was likely ordered by the crown prince.

The royal said in a recent interview with The Atlantic that it was “obvious” he had not ordered it.

“It hurt me a lot,” MBS said. “It hurt me and it hurt Saudi Arabia, from a feelings perspective.

“I understand the anger, especially among journalists. I respect their feelings. But we also have feelings here, pain here.”

At a presidential election debate in Nov 2019, Mr Biden said he would make the Saudis “pay the price” for the killing of Khashoggi.