The UK has licensed some £4.6bn worth of arms to Saudi Arabia, including £2.66bn in value of aircrafts, helicopters and drones, as well as £1.9bn in grenades, bombs and missiles.

The Campaign Against Arms Trade (CAAT) appeal is being brought against Liam Fox, secretary of state for international trade, for allowing export licenses amid allegations of war crimes by Saudi Arabia in Yemen.

Andrew Smith, media coordinator of CAAT, said: “The Saudi-led bombardment of Yemen has killed thousands of people and created one of the worst humanitarian disasters in the world.

“Despite this, the Saudi regime has been armed and supported every step of the way by successive UK governments.

“We believe that these arms sales are immoral and are confident that the Court of Appeal will agree that they are unlawful.”

The group’s lawyers argued that the decision to allow such licenses was against the UK arms export policy, as there is a “clear risk” that the arms “might” be used in “a serious violation of international humanitarian law”, as set out in the policy.

More than 10,000 people have been killed in the conflict in Yemen, with millions facing starvation and disease.

In October 2016, the UK’s international development and business, innovation and skills select committee said: “Given the evidence we have heard and the volume of UK-manufactured arms exported to Saudi Arabia, it seems inevitable that any violations of international humanitarian and human rights law by the coalition have involved arms supplied from the UK. This constitutes a breach of our own export licensing criteria.”

The campaign group took its legal case to the Court of Appeal on 12 April to overturn an earlier High Court judgment, which allowed the government to continue to export arms to Saudi Arabia for use in Yemen.  

Court of Appeal judges have now granted CAAT’s appeal and the case is expected to be heard in the next few months.