Saudi Arabia and the UK's roles in the Yemen conflict in the spotlight on Wednesday (March 7) as the Gulf kingdom's Crown Prince Mohammed Bin Salman arrived in London for a high-profile visit.
His trip prompting protests outside the British parliament and a fiery exchange inside.
Before meeting the crown prince, British Prime Minister Thereasa May was forced to defend the UK-Saudi relationship:
(SOUNDBITE (English) UK PRIME MINISTER, THERESA MAY, SAYING:
"The link that we have with Saudi Arabia is historic, it is an important one, and it has saved the lives of potentially hundreds of people in this country,."
Her comments met with cries of "shame" from the opposition benches and this acccusation from her opposition counterpart.
(SOUNDBITE) (English) LABOUR LEADER, JEREMY CORBYN, SAYING:
"It cannot be right that her government is colluding in what the United Nations says is evidence of war crimes."
That accusation refering to British support for the Saudi-led campaign in Yemen including the licensing of $6.4bn worth of arms sales to the kingdom since the start of the conflict.
Saudi Arabia is battling the Iran aligned Houthi movement in Yemen - and the United Nations says its airstrikes have killed civilians.
May intends to bring up the humanitarian situation with the Saudi heir at a private dinner, her spokesman said.
Britain and Saudi Arabia have much to gain from improved ties.
Saudi Arabia needs to convince skeptical international investors about its domestic reforms, and the UK is looking for increased trade as it exits the European Union.
London is also vying for the partial listing of Saudi Aramco - the state oil firm that Prince Mohammed has said is worth $2 trillion, meaning listing just five percent of the company could raise $100bn.
And the Prince has been courted with displays of diplomatic affection including sitting down for lunch with Queen Elizabeth - a rare honor usually only granted to heads of state.