It has been over three years since Saudi-led forces began their devastating bombardment of Yemen, with the destruction having already created what the UN General Secretary has described as the ‘world’s worst humanitarian crisis.’

Thousands of people have been killed as a direct consequence of the war, and many more from preventable causes as a result of the catastrophe that has taken root. Horrifying research from Save the Children has found that 50,000 children died from hunger or disease in 2017 alone.

Now the war has reached an even more deadly stage, with the Saudi-led coalition having began strikes against Hodeidah, the biggest port town in Yemen. It has provided a vital lifeline for many across the country, with over 70% of Yemen’s imports, food and aid shipments flowing through it.

The importance of the port was underlined last year when Saudi-forces imposed a strict blockade. Vital good were stopped from entering, and, despite some easing over recent months, food and fuel deliveries are still way beneath the levels that Yemen needs.

Such an attack could be devastating. Save the Children has said that vital aid will be cut-off and a further 340,000 people could be displaced. Last Friday the UN warned that the worst case scenario could see 250,000 people killed.

Even the UK government has raised reservations about the plan. The Middle East Minister, Alastair Burt, said he is “extremely concerned” that aid agencies are not getting the security guarantees they need, and has called for all parties to the conflict to “allow safe, rapid and unhindered humanitarian access to all parts of Yemen.”

Despite their professed concerns, Burt and his colleagues have refused to reconsider their uncritical political and military support for the Saudi-led coalition. The reality is that UK fighter jets and missiles are almost certainly being used in the assault.

Since the war began the UK government has licensed over £4.6billion worth of arms to the Saudi regime, and many more to the United Arab Emirates and the other militaries that have taken part in the bombing.

This has been complemented by a fawning political relationship that saw the Saudi Crown Prince, Mohammad Bin Salman, given the full red carpet treatment when he visited the UK in February. Theresa May and her colleagues have routinely defended their relationship with the Crown Prince, despite the leading role he has played in the war.

Bin Salman has told Time magazine that Saudi forces are “doing our best to be sure that the interests of the people in Yemen — health care, education, whatever — it’s supported.” However, at the time of writing, Saudi-led forces have just destroyed an MSF-run cholera treatment centre in Yemen.

This wasn’t a one-off incident. A United Nations Expert Panel has accused the regime of “widespread and systematic” attacks on civilian infrastructure right from the start. None of this bodes well for the terrible destruction that could be inflicted on Hodeidah in the days ahead.

If the UN’s worst predictions become a reality then those that have armed and supported the conflict cannot say that they were not warned.

Governments like the UK have not been mere bystanders in the chaos: they have been active participants. This war could never have been fought without their complicity and compliance. When faced with a choice between the rights and lives of Yemeni people and arms company profits, government ministers have consistently supported the latter.

UN Special Envoy Martin Griffithswarned that any strikes on the port town could take peace off the table “in a single stroke” and yet the arms sales have continued. We are always being told about the influence that Downing Street carries with the Saudi regime. If that really is the case then it’s time for them to use it for good.

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