A 'memorandum of intent', which aims to finalize the deal, was signed on Friday between the government and the nation's Crown Prince Mohammed bin Salman as he completed a three-day visit to the UK, mirror.co.uk reported.
BAE Systems, the British defense giant producing the jets, employs 5,000 people on its Typhoon program in the UK.
But campaigners have spent days calling for Britain to suspend arms sales to the Persian Gulf state.
Politicians from the UK's main opposition party called for an end to arms sales to Saudi Arabia, calling the sale of the Eurofighter Typhoon jets to the kingdom a "national disgrace".
Kate Osamor, the shadow international development secretary, denounced a provisional agreement signed between the two countries, as the kingdom remains embroiled in a bloody bombing campaign in Yemen that has killed thousands of civilians and precipitated a humanitarian crisis, aljazeera.com reported.
"[Prime Minister] 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.
Since the start of the war in Yemen, the UK has approved arms export licenses to Saudi Arabia worth $6.3bn, including the sale of Tornado aircraft, tanks, armored 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 antiwar 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 numbers of missiles.
Kate Allen, Amnesty International UK’s Director, said: “Selling more fighter planes to a country leading a military coalition that’s 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 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.
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.
However, Chief executive Charles Woodburn called the Friday's weapons news a "positive step", while Defence Secretary Gavin Williamson said it would " increase security in the Middle East and boost British industry and jobs".
Campaign Against Arms Trade
Andrew Smith of Campaign Against Arms Trade said: “If agreed this shameful deal will be celebrated in the palaces of Riyadh and by the arms companies who will profit from it, but it will mean even greater destruction for the people of Yemen.
"For decades now, successive UK governments have enjoyed a toxic and damaging relationship with the Saudi regime.
"By rolling out the red carpet for the Crown Prince, Theresa May has shown how low she will sink to maintain it."
Save the Children
Save the Children chief executive Kevin Watkins said Saudi Arabia is targeting children in Yemen with a "growing sense of impunity", and claimed the Saudis were "orchestrating what will potentially become the worst famine in the last 50 years".
Speaking in London he added: "It has become acceptable to operate humanitarian blockades which, if not explicitly designed to starve children and harm children, will have that inevitable consequence.
"We have the head of state of a government that has been operating such a blockade - Saudi Arabia - recently invited to Buckingham Palace and Downing Street while the military ... is orchestrating what will potentially become the worst famine in the last 50 years.
"I think speaks volumes to another aspect of the problem that I want to highlight - the growing sense of impunity surrounding these crimes against children.
"The fact that you can rape, murder, kidnap, bomb schools, bomb clinics with no consequence, speaks I think to the heart of the deeper challenge that we are addressing today."
UK Labour leader Jeremy Corbyn earlier this week accused the British government of "colluding" in what was described as "evidence of war crimes."
"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."
The Labour leader told Theresa May at Prime Minister's Questions: "Millions face starvation. 600,000 children have cholera because of the Saudi-led bombing campaign and blockade.
Downing Street said May did raise her "deep concerns at the humanitarian situation in Yemen" during her meeting with the crown prince.
Saudi Arabia’s war on Yemen has killed more than 10,000 people since 2015, displaced more than two million and destroyed much of the country’s infrastructure, including the health system.
The Saudi war was launched in March 2015 in support of Yemen’s former Riyadh-friendly government and against the country’s Houthi Ansarullah movement.
The Saudi-led campaign, which was accompanied by a land, aerial and naval blockade of Yemen, has so far killed more than 13,600 people and led to a humanitarian crisis.