THERESA May has come under pressure from the SNP and Labour as she arrived in Saudi Arabia yesterday on the latest leg of her tour around the Middle East to promote trade links.

She was quizzed by journalists ahead of departing for the Saudi capital Riyadh about the kingdom’s involvement in a long running war in neighbouring Yemen. But the Prime Minister said the country’s ties with the UK are important for security and prosperity.

Human rights groups have repeatedly criticised the UK Government for supporting for the Saudi-led coalition in the area where more than 4,600 people have died and a humanitarian crisis has affected 18 million.

The UK Government has exported £3.3billion of military equipment to Saudi Arabia since March 2015 despite growing concerns over the indiscriminate bombardment of towns and cities and civilian infrastructure.

“We are concerned about the humanitarian situation - that’s why the UK last year was the fourth largest donor to the Yemen in terms of humanitarian aid - £103m. We will be continuing with that,” she told the BBC as she prepared to fly out for the two day visit from Jordan.

“And yes, we will be raising the humanitarian issue. We believe it is important that we recognise the threat that there is in terms of people’s lives. We will be supporting that through the aid and support that we give.”

Tasmina Ahmed-Sheikh MP, the SNP’s International Trade spokeswoman, said May’s comments highlighted the direction the “morally defunct UK government is intent on steering this country towards”.

She said: “It is beyond words that the Prime Minister is proud of a relationship that sees the UK selling arms and military equipment with one hand and handing aid to its victims with the other.”

Labour Party leader Jeremy Corbyn also criticised the visit saying UK-made weapons were contributing to a “humanitarian catastrophe”.

May eschewed the strict Saudi Arabian dress code for women by declining to wear a head scarf as she arrived in Riyadh, stepping off her plane with her hair showing. She said she would be a role model for oppressed women in Saudi.

Meanwhile, in a separate development May called for an investigation into a suspected chemical weapons attack in Syria as she condemned the atrocity which has claimed the lives of dozens of people.

The Prime Minister called on Russia to ensure Bashar Assad’s regime is brought to an end.

Opposition activists claim that dozens of people died in the attack in a town in the northern province of Idlib, with the British-based Syrian Observatory for Human Rights putting the death toll at 58, including 11 children.

May said: “I’m appalled by the reports that there’s been a chemical weapons attack on a town south of Idlib allegedly by the Syrian regime. We condemn the use of chemical weapons in all circumstances.

“If proven, this will be further evidence of the barbarism of the Syrian regime, and the UK has led international efforts to call to account the Syrian regime and Daesh for the use of chemical weapons and I would urge the Organisation for the Prohibition of Chemical Weapons to investigate this incident as soon as possible.

“I’m very clear there can be no future for Assad in a stable Syria which is representative of all the Syrian people and I call on all the third parties involved to ensure that we have a transition away from Assad. We cannot allow this suffering to continue.”

Foreign Secretary Boris Johnson denounced the attack as a “war crime”, calling for those responsible to be brought to justice. It would be “unbelievable” for Assad to play a role in the post-war government of the country if his regime is found to be to blame, he said.