Last Sunday marked 500 days since Saudi Arabian forces intervened in the Yemeni civil war. In that time, Saudi air strikes have killed thousands of people, destroyed vital infrastructure and unleashed a humanitarian crisis on the civilian population.

The UN has ranked the humanitarian situation as a “Level 3” emergency - the highest possible emergency ranking - yet all attempts to negotiate a peace deal have fallen apart. The most recent negotiations have just ended in a stalemate. Since then 14 people have been killed in the bombing of a food factory.

This was the most recent in a long series of devastating aerial assaults. 500 days of bombs being dropped from the skies has ensured that almost nowhere is safe, with a refugee camp, a wedding and a market having all been hit in the bombardment.

More than 2.5 million people have been displaced, while schools, hospitals and cultural heritages sites have been destroyed. Of those who remain in Yemen, millions have been left without access to clean water or electricity, and 80% of the population has been left in need of aid.

There is no question that atrocities have been committed on all sides of the conflict, although the UN has accused Saudi forces of killing twice as many civilians as all other forces.

Despite the carnage, the response of governments like the UK has been to fuel the destruction with arms sales and an uncritical political support. The UK specifically has provided training and political support, while licensing billions of pounds worth of arms to the Saudi regime.

These arms sales haven’t just been immoral, they have also been illegal. Arms exports control regulations are very clear: a licence should not be granted in the circumstances where there is a “clear risk” that it “might” be used to violate international humanitarian law. In spite of this, the UK has licensed over £3.3 billion worth of arms sales to Saudi Arabia since the bombing began, including fighter jets, bombs and missiles.

There is no doubt that UK-made arms have had a devastating impact, with a recent investigation by Human Rights Watch linking Paveway IV bombs, made in the UK, to attacks on businesses and civilian targets.

A recent UN report accused Saudi forces of deliberately bombing a house, killing four children in the process. “It is almost certain that the civilian house was the deliberate target of the high explosive aircraft bombs,” said the report. It concluded that the coalition had failed to take precautions and “thus violated international humanitarian law.”

At the same time, the Saudi-led coalition published its own report into accusations of war crimes. Needless to say its findings were largely an exercise in self-justification and evasion, but even it had to acknowledge what it referred to as ‘shortcomings‘ in the conduct of the bombing.

One of the cases it cited as a ‘mistake’ was the bombing of a residential compound that killed 65 people. The language is distasteful and the regrets feel forced and superficial, but the fact that even the Saudi authorities feel the need to concede hitting civilian targets is a sign of how overwhelming the evidence has become.

In the last hours of the last day of the most recent session of parliament, the government performed a major U-turn by publishing written corrections that reveal, contrary to earlier claims, that there has been no oversight of how arms are being used. At best it represented staggering incompetence on the part of government ministers— at worst it was a cynically timed admission of how they had previously distorted the truth.

Either way, it underpins the point that the Saudi government hasn’t just bought arms and military support, it has also bought silence, compliance and a seal of political approval.

For decades now, successive UK governments have worked hand in glove with the arms companies and Saudi authorities, continuing to sell arms and provide political support while choosing to ignore the grotesque human rights abuses that are being carried out every single day.

The arms sales themselves are now subject to a Judicial Review, following an application by Campaign Against Arms Trade, with a full three-day investigation scheduled to take place in front of two judges no later than February 1st 2017.

This will be the first time that UK arms export policy has been put under the spotlight and scrutinised in this way. It is an unprecedented step that is likely to focus on not just the extent of UK arms sales to Saudi, but also the scale of collusion and government support that goes with it.

In the meantime, there is no question that the government will pull out all stops to continue arming and supporting its most shameful ally. Time and again, and particularly over the last 500 days, it has proven that it will go to any length (or sink to any low) in order to maintain a terrible status-quo.

Andrew Smith is a spokesperson for Campaign Against Arms Trade (CAAT). You can follow CAAT at _at_CAATuk.