Politicians from the UK's main opposition party have denounced a $140 million humanitarian deal with Saudi Arabia, saying it "made a mockery" of Britain's reputation as a global leader in delivering humanitarian aid.

Kate Osamor, the shadow international development secretary, denounced an agreement signed between the two countries on Friday, as the kingdom remains embroiled in a bloody bombing campaign in Yemen that has killed thousands of civilians and precipitated a humanitarian crisis.

The $140 million deal is aimed at creating vital infrastructure in drought and conflict-stricken countries, but the was greeted with fury by opposition MPs over Saudi Arabia's role in the Yemen conflict.

"Theresa May implied she would lobby Mohammad bin Salman to stop bombing civilians and end the use of starvation as a weapon of war," Osamor told the Guardian newspaper.

"Over 22 million Yemeni lives depend on permanent, full access for aid, food and fuel in Yemen. Instead, she has won no concessions and simply handed on a plate to Saudi Arabia a new humanitarian partnership and an endorsement from DfID [the Department for International Development], the world's best aid agency.

"It will whitewash Saudi Arabia's reputation and role in the war, and it is a national disgrace," Osamor said.

Osamor's comments came as Downing Street also announced plans to sell 48 Eurofighter Typhoon jets to Riyadh.

Since the start of the war in Yemen, the UK has approved arms export licences to Saudi Arabia worth $6.3bn, including the sale of Tornado aircraft, tanks, armoured vehicles, grenades, missiles and bombs.

The Saudis already operate 72 Typhoons from a first batch of jets ordered in 2007, despite previous concerns raised by human rights groups and anti-war campaigners.

The fighter jets are considered the most advanced swing-role combat aircraft currently available and have a top speed of more than 1,500mph and carry a large number of missiles.

'Colluding in war crimes'

Labour leader Jeremy Corbyn has repeatedly denounced the arms deals and earlier this week accused Prime Minister Theresa May of "colluding" in war crimes by selling weapons to Riyadh.

"Germany has suspended arms sales to Saudi Arabia, but British arms sales have sharply increased and British military advisers are directing the war," Corbyn told May during Prime Minister's Questions at the House of Commons.

"It cannot be right that her government is colluding in what the United Nations says is evidence of war crimes."

Amnesty International also slammed the agreement, saying: "Selling more fighter planes to a country leading a military coalition that is already laying waste to homes, hospitals and schools in Yemen, is just adding fuel to a humanitarian fire."

Friday's weapons announcement comes after Saudi crown prince Mohammed bin Salman wrapped up his controversial state visit to the UK which drew angry protests and calls for his arrest over his role in the Yemen war and the blockade of Qatar.

The Saudi crown prince, who is accused of being the "chief architect" of the war, arrived on a three-day visit on Wednesday, with the ruling Conservative Party and the UK's royal family rolling out a red carpet for the young heir to the throne.

In the lead-up to the trip, tens of thousands of Britons had signed online petitions calling on Theresa May, the prime minister, to cancel bin Salman's visit over his actions towards his southern neighbour.

According to Save the Children and UNICEF, at least 110,000 children have died from preventable causes brought about by the war in just the last two years.