Boris Johnson has been given another slap down by Downing Street after the UK foreign secretary accused Saudi Arabia, a British ally, of engaging in "proxy wars" in the Middle East.

The prime minister's spokesperson told reporters that Johnson's comments were a "personal view" and "not the government's position" on Saudi Arabia and the region.

The awkward comments came to light after The Guardian released a recording of the top diplomat speaking at the 2016 Mediterranean Dialogues conference in Rome, Italy, last week.

"There are politicians who are twisting and abusing religion and different strains of the same religion in order to further their own political objectives," Johnson reportedly said.

"That's one of the biggest political problems in the whole region. And the tragedy for me – and that's why you have these proxy wars being fought the whole time in that area – is that there is not strong enough leadership in the countries themselves."

He later added: "That's why you've got the Saudis, Iran, everybody, moving in, and puppeteering and playing proxy wars."

The critical remarks risk creating a diplomatic row with Saudi Arabia, just days after Theresa May travelled to another Middle Eastern ally, Bahrain.

Shadow Foreign Secretary Emily Thornberry urged the government to provide "consistent principles" in light of Johnson's comments.

"For months, Labour has been arguing that what last year began as an UN-backed attempt to restore the government of Yemen has now descended into a brutal and indiscriminate proxy war, and a desperate humanitarian crisis, with the lives of hundreds of thousands of children at risk," she said.

"That argument has consistently been rejected by Boris Johnson in the House of Commons, but now these remarks in Italy have shown us what he really thinks.

"If that is his genuine view, he needs to explain why he ordered his MPs to vote against Labour's calls in October to suspend support for the Saudi-led coalition in Yemen, until a lasting ceasefire has been brokered and until alleged violations of international humanitarian law have been properly investigated."

She added: "The government cannot complain about Saudi Arabia's military actions one minute, then continue selling it the arms to prosecute those actions the next. We need to see some consistent principle in the UK's foreign policy, not more shabby hypocrisy."