Imagine how this government would have reacted if last weekend either Russia or Iran had abducted – and in all likelihood murdered – one of their dissident journalists within the sovereign territory of another country.

In fact, we do not need to imagine it. We need only look back five months to the faked assassination of the Russian journalist Arkady Babchenko on the streets of Kiev. It took the then foreign secretary, Boris Johnson, less than 24 hours to issue an official statement not only saying how appalled he was, but leaving no doubt that the Russian state was responsible and saying it must be held to account.

Jamal Khashoggi: Labour slams government’s response as ‘too little, too late’ Read more

Roll forward to the disappearance of the Saudi dissident journalist Jamal Khashoggi from his country’s consulate in Istanbul. From the time he went missing on 2 October, it took Johnson’s successor, Jeremy Hunt, seven days to issue a tweet saying he was seeking urgent answers from the Saudi authorities, and that “if media reports prove correct, the government will treat the incident seriously”.

That is the definition of far too little, far too late. But that is the pattern when it comes to this government’s relationship with the current Saudi regime, led by Crown Prince Mohammed bin Salman, so feted and fawned over by Theresa May when he visited the UK this summer. And yet this man is the architect of the war in Yemen, directly responsible for the deaths of thousands of civilians as a result of airstrikes and humanitarian blockades, including the dozens of children killed on their school bus in August, someone who, by any reasonable standards, should be the subject of an investigation for crimes against international humanitarian law.

Facebook Twitter Pinterest Jamal Khashoggi went missing on 2 October after entering the Saudi embassy in Turkey. Photograph: Mohammed Al-Shaikh/AFP/Getty Images

He presides over what is projected to be the biggest year of beheadings in Saudi Arabia’s history, including forcing those brutal executions on women and men simply for protesting for greater civil, political and religious freedoms. He is the prince so sensitive to criticism that he is forcing through a law that will punish any individual distributing satire on social media that “mocks, provokes or disrupts public order, religious values and public morals”, with prison sentences of up to five years and fines of up to £623,000.

And he is the so-called diplomatic genius who last year lured the prime minister of Lebanon to Riyadh on the pretext of taking a bonding camping trip, then had him beaten up and paraded in front of the cameras to make a forced televised resignation, thankfully later rescinded.

This man has no respect for human rights, no respect for the rule of law and no respect for territorial boundaries, so is it any wonder so many commentators are convinced he had no hesitation in ordering the abduction and murder of Khashoggi? And yet this government apparently urges us to forget all of that because Bin Salman has committed himself to allowing women in Saudi Arabia to have the right to drive their own cars. And, more importantly, as far as it is concerned, he will give us a good trade deal after Brexit so we can continue exporting the arms he is using to prosecute his brutal war against the people of Yemen.

We should not be in league with a brutal dictatorship that beheads its own citizens

Well, I am not having it, the Labour party is not having it and I don’t think the British people are having it either. We should not be in league with a brutal dictatorship that beheads its own citizens for standing up for their rights, which rains down airstrikes on civilian areas in Yemen with no concern for innocent children, and that thinks it can assassinate dissident journalists in other countries with impunity. We must apply the same standards to countries such as Saudi Arabia, Israel and Egypt that we apply to Iran, Russia and Syria.

Where any of them abuse human rights and breach international humanitarian law, we must be prepared to call it out in the same measure, rather than treating it as one rule for our supposed friends and another for our supposed enemies.

Saudi isolation grows over Khashoggi disappearance Read more

When Robin Cook set out to apply an “ethical dimension” to British foreign policy just over 20 years ago, it was arms sales to countries in the Middle East that he had in mind and when he was forced to drop that policy a few years later, to his great sadness, it was in part as a result of pressure over the impact on exports to Saudi Arabia.

The next Labour government, under Jeremy Corbyn’s leadership, will not make that compromise. It is time to end Britain’s blind spot on Saudi Arabia until Saudi Arabia is genuinely ready to change its ways.

• Emily Thornberry is shadow secretary of state for foreign and Commonwealth affairs