Labour leader, Jeremy Corbyn, has accused the British military of directing the war in Yemen.
The controversial comments were made this week during Prime Minister’s questions.
Mr Corbyn said: “British arms sales have sharply increased and British military advisers are directing the war.”
“Will the Prime Minister use her meeting today with the Crown Prince to halt the arms supplies and demand an immediate ceasefire in Yemen?”
“It cannot be right that her government is colluding in what the United Nations says is evidence of war crimes.”
A spokesman for Mr Corbyn later said he had been referring to the presence of British military personnel to advise on targeting by the Saudi air force attacking the Houthi rebels.
He said: “British military advisers advise the Saudi military on targeting and so there is a direct involvement in the conduct of the war.
“British military personnel are in the operations room where these bombing campaigns are being conducted. They are advising directly on the targeting of infrastructure and operations in Yemen.”
“The spokesman added: “The British Government is colluding with this military campaign and that includes the disastrous humanitarian effects of the aerial operations.”
A spokesman for the PM said claims British military advisers are directing the war is “simply not true.”
“The UK is not a member of the Saudi-led coalition operating in Yemen,” they said.
“British personnel are not involved in carrying out strikes, directing or conducting operations in Yemen and are not involved in the Saudi targeting and decision-making process.
“We have a long-standing relationship with Saudi Arabia in terms of supporting Saudi compliance with international humanitarian law and in armed forces training.”
Responding to Mr Corbyn in the House of Commons, Theresa May told the Labour leader she was “concerned about the appalling humanitarian situation in Yemen.”
She highlighted how more than £200m in aid made the UK the third largest humanitarian donor in Yemen.