BORIS Johnson is facing calls to cancel his visit to Saudi Arabia following the execution of 81 people, which left the UK government “shocked”.

The Prime Minister is preparing to visit Riyadh to Crown Prince Mohammed bin Salman in the hope his kingdom can raise its production of oil and gas to make up for a reduced reliance on Russia.

However, Mr Johnson was warned by MPs he will face “exquisite difficulties” given he will arrive just days after the executions, with Tory former minister Crispin Blunt pressing the PM to make clear Britain’s concerns.

Mr Blunt said the execution of 81 men in a day – reported by the state-run Saudi Press Agency on March 12 – is “of profound concern” to the Commons and the country.

He told MPs: “This represents a new low for human rights and criminal justice in the kingdom, coming only a week after the Crown Prince had promised to modernise the Saudi justice system.”

Liberal Democrat former minister Alistair Carmichael warned: “Actions do speak louder than words.

“If the Prime Minister goes in the next few days to Saudi Arabia, we will be sending a very clear signal that no matter what we say, we’re not really bothered about this sort of thing.”

Foreign Office minister Amanda Milling replied: “Given our relationship with Saudi Arabia, we are able to have those frank conversations about human rights. We are opposed to the death penalty in all countries under all circumstances.”

Conservative Julian Lewis (New Forest East) called on the Government to confirm that “in seeking to lessen our dependence upon one source of oil and gas, we do not end up creating a source dependency on another unreliable and sometimes hostile regime”.

Ms Milling said: “It’s important that all international partners work together to ensure the stability of energy markets.”

The Green Party MP for Brighton Pavilion Caroline Lucas asked: “Does she not see any contradiction between rightly ending dependence on Putin’s Russia for fossil fuels, but then seeking to replace them by going cap in hand to another murderous tyrant who executes his own people and to whom we sell arms that are being used to kill civilians in Yemen?”

Earlier, Ms Milling told MPs: “We are shocked by the execution of 81 individuals. The United Kingdom strongly opposes the death penalty in all countries and in all circumstances as a matter of principle.

“The UK ambassador has already raised the UK’s strong concerns with the Saudi national security adviser and their vice-foreign minister.”

Ms Milling said the UK will seek further clarification on the cases, adding: “No aspect of our relationship with Saudi Arabia prevents us from speaking frankly about human rights.”

The Saudi Press Agency said the executions included people “convicted of various crimes, including the murdering of innocent men, women and children”.

The kingdom also said they included members of al Qaida, the so-called Islamic State terror group and backers of Yemen’s Houthi rebels.