David Cameron is today making his first visit to Saudi Arabia since becoming Prime Minister.
Cameron will meet King Abdullah and Crown Prince Nayif in talks which Downing Street hopes will "broaden and deepen" the UK-Saudi relationship.
Saudi Arabia is Britain's biggest trading partner in the Middle East with bilateral trade worth £15bn a year and Saudi investment in the UK worth more than £62bn.
The government sees strong relations with the Saudis as vital to advancing Britain's interests in the region on a range of issues including energy security, counter-terrorism and political reform.
Cameron's visit comes as a powerful group of MPs raised concerns about British arms sales to Saudi Arabia.
The Committees on Arms Export Controls published questions it has submitted to the government over the licensing for a range of equipment, including bomb equipment, components for military combat vehicles and helicopters, weapon sights and communications technology.
MPs questioned why, given the unrest in Saudi Arabia early last year, licences had not been revoked as part of the government's review of arms sales to the Middle East and North Africa.
They asked: "Why does the UK believe that the assurances relating to end-use will not be breached?"
Meanwhile, foreign secretary William Hague has warned that Britain "must respect" the choices made by voters in countries that have ousted repressive regimes, even if they are considered extremist by the West.
In an article for The Times, he said: "It is true that parties drawing their inspiration from Islam have done better at the polls than secular parties and there are legitimate concerns about what this will mean...
"We must respect these choices while upholding our own principles of human rights and freedom and urging the highest standards.
"Trying to pick winners would fatally undermine faith in our intentions and our support for democracy. In standing up for the right of peoples to choose their own representatives at the ballot box, we have to accept their choices and work with the Governments they elect."
Last year Cameron avoided meeting officials from Egypt's Muslim Brotherhood, calling them "extreme".