And so the Brexit cavalcade gathers pace. After paying court to Donald Trump in Washington on Friday, Theresa May will fly to Turkey to meet another hard man with a weakness for “alternative facts”: President Recep Tayyip Erdoğan, who has engaged in a brutal clampdown on human rights that has shocked capitals around the world. Except, apparently, London, where the Conservative Brexit government is so desperate for trade deals with anyone but the mature democracies of the European Union that even the most unsavoury rulers are to be subjected to the prime ministerial charm.

Turkey has more journalists in prison than any other country in the world. But then Saudi Arabia and Oman, where Liam Fox has been scouting for trade deals, are hardly beacons of human rights.

This tawdry tour shames Britain. This is a defining period on the international stage and we must consider to what extent this new course is safeguarding both our interests and values around the world.

In an age of “alternative facts”, there is no doubt about the realities of the Erdoğan regime. Even before last July’s failed coup, Erdoğan had begun systematically dismantling Turkey’s democratic institutions. Since the coup, he has embraced full-frontal authoritarianism. He is not only locking up journalists, but teachers, professors and policemen – all without due process. Not quite the outfit you’d have in mind for a regime described yesterday as an “indispensable partner” by Theresa May.

Indeed, turn the clock back eight months and our now foreign secretary was slating the Turkish president. Yet Boris Johnson has fallen unusually silent – refusing to call Erdoğan out on his shocking crimes. There is a pattern here: ministers pursuing business deals on the international stage at odds with Britain’s best traditions and values.

The Tories are ignoring breaches of international humanitarian law in Yemen for an arms and trade deal with Saudi Arabia. May is cosying up to an American president who not so long ago she was criticising for his anti-Muslim diatribes. Far from defending liberal values, the Conservatives are happy to sell them to the highest bidder, or indeed any bidder.

To stave off complete isolation, ministers are engaged in a desperate trawl around the globe for trade deals that might just plug some of the mind-bogglingly massive Brexit black hole in our economy, which latest estimates put at up to £200bn over the next 15 years.

Perhaps nothing crystallised this more than the sight of craven ministers boasting of their meeting of minds with President Trump. This would be embarrassing even without footage of Michael Gove being roundly rejected on his “front of the queue” plea to Trump.

The Conservative strategy is both short-sighted and dangerous, not only damaging the UK’s global reputation but missing the point that liberal, democratic societies are more stable, less volatile and all round better trading partners. It is in both our economic and security interests to encourage the pursuit of human rights, rule of law and democracy precisely because those things make the world safer.

Compare the mean-spirited, transactional rhetoric of ministers with the dignified response of Angela Merkel and François Hollande to Trump’s disparaging of Nato and the EU, and it raises serious questions about May’s priorities.

The problem is that May has decided – it wasn’t a condition of the referendum – to withdraw from the world’s largest single market. Britain’s economy flourished while trading with our 27 democratic neighbours in a framework of rules created by Britain. Our citizens have benefited from human rights, freedom of speech and working conditions being protected by Europe. No deal will secure our interests and keep us as economically strong as the deal we currently have – in the European Union.

This is not a strong, confident government, it is a shifty, grubby regime, tin-eared to the views of our friends and brainwashed by the Ukip world view. Is this really what people imagined of life outside the EU? Whether you were leave or remain, it should be deeply troubling to see ministers pursue a strategy both damaging to our economic interests and undermining of our best and most cherished values.

That is why Liberal Democrats will not simply fall behind the government in pursuing a hard Brexit. Unlike Labour, we will vote against article 50 if the people are not given a say on the final deal. Nor will we turn our backs on our friends in Europe at the expense of strongmen with weak principles around the world.

Last year I stood for parliament in a by-election for Richmond Park and North Kingston because I believed unashamedly in the values of liberalism, and the strong economic and social society that this creates. Those values are now in jeopardy, and progressives must rally to protect them.