The United Kingdom’s government announced on Monday that Britain’s multi-billion-pound arms sales to Saudi Arabia has been ruled as lawful by the High Court after it examined confidential evidence.

The court rejected the bid on ministers having acted illicitly when not suspending weapon sales to the Kingdom of Saudi Arabia.

The government said defense exports would continue to be reviewed, but the Campaign Against the Arms Trade (CAAT) said an appeal against the ruling was planned.

CAAT had sought an order to block export licenses for British-made bombs, fighter jets and other munitions which it said the Saudi-led Arab coalition was using in a campaign against Iranian-backed Houthis in Yemen’s civil war.

Lord Justice Burnett and Sir Justice Haddon-Cave, sitting in London, said the decision to carry on the arms trade was not unlawful.

The judges said “closed material”, which had not been made public for national security reasons, “provides valuable additional support for the conclusion that the decisions taken by the secretary of state not to suspend or cancel arms sales to Saudi Arabia were rational”.

Iran-backed Houthi coupists, and armed loyalists aligned with deposed president Ali Abdullah Saleh, began an attack in 2014, forcing the constitutionally elected President Abdrabbuh Mansour Hadi to flee the country for a time.

Since then the Saudi kingdom, and eight other mostly Arab states, have supported an air campaign aimed at reinstating Hadi’s government to power.

The government said UK defense exports would continue to be “under careful review” to ensure they meet the standards of the Consolidated EU and National Arms Export Licensing Criteria.

“We welcome this judgment, which underscores the fact that the UK operates one of the most robust export control regimes in the world,” a spokesperson said.