David Cameron personally visited the Oxfordshire mansion of Saudi Arabia’s intelligence chief in hope of persuading the kingdom to push Barack Obama into action against the Syrian regime, it has emerged.

The former prime minister spoke to the son of Prince Bandar bin Sultan, asking him to pass a message to his father that “Obama is not serious in Syria”.

He lamented how British and French calls for the US president to take a stronger position had fallen on deaf ears, but that things might change if Riyadh called the White House.

In an interview with Independent Arabia, Prince Bandar revealed that the message did eventually make it back to the then-king Abdullah bin Abdulaziz al Saud.

The story relates to the period after August 2013 in which the Syrian regime of Bashar al-Assad stood accused of a chemical weapons attack near Damascus that killed hundreds of people, including more than 400 children.

Saudi Arabia opens its first women-only hotel Show all 4 1 /4 Saudi Arabia opens its first women-only hotel Saudi Arabia opens its first women-only hotel A room at the Luthan Hotel and Spa in the Saudi Capital Riyadh HASSAN AMMAR/AFP/Getty Images Saudi Arabia opens its first women-only hotel A receptionist at Luthan Hotel and Spa poses for pictures during the opening ceremony in the Saudi Capital Riyadh HASSAN AMMAR/AFP/Getty Images Saudi Arabia opens its first women-only hotel A Saudi woman explores the new hotel HASSAN AMMAR/AFP/Getty Images Saudi Arabia opens its first women-only hotel Two women attend the hotel's opening ceremony HASSAN AMMAR/AFP/Getty Images

The attack also crossed a diplomatic “red line” set out by Mr Obama, leaving him having to decide whether to take military action in Syria in the face of domestic opposition to a new offensive in the Middle East.

As the situation developed, Mr Cameron is said to have visited the Glympton estate of Saudi intelligence chief Prince Bandar, whom the then-PM had a working relationship with, though on this particular occasion he ended up speaking to his son.

The prince told Independent Arabia editor Adhwan Alahmari that the prime minister had “passed by” and stopped in to ask for a meeting, after which his son went out to speak with Mr Cameron.

The prince added: “They went to a small cottage in a lake in front of the house. He was without bodyguards and my son shook his hand. Cameron asked my son to go for a walk and then asked him, ‘Is there a way to contact your father?’

“[My son] said, ‘Yes, why?’. He said, ‘I want you to tell him that Obama is not serious in Syria, and he will not do anything. We’ve tried with the French and there have been great efforts. Obama refuses to listen to us. If it’s possible for Saudi Arabia to make some effort, action may be taken.’”

The prince said that his son told the prime minister he was not involved in his father’s work, but accepted that a message did find its way back to the Saudi king following the meeting.

The story casts light on the diplomatic channels to the Middle Eastern state that were open to the former prime minister, with Prince Bandar’s mansion conveniently located in his Witney constituency and the Saudi official’s son married to a family friend.

A spokesman from the office of Mr Cameron said: “David Cameron met with Prince Bandar bin Sultan on several occasions both as leader of the opposition and prime minister; the Glympton estate was in his west Oxfordshire constituency.

“He also knows his son, who married a family friend. Mr Cameron did meet Prince Bandar’s son at Glympton but cannot confirm the report of the conversation”.

In the end, the House of Commons refused to support air strikes in Syria ending Mr Cameron’s intention of tackling the Assad regime head on.