Donald Trump’s capacity for stoking hatred knows no bounds. His endorsement yesterday of anti-Muslim tweets by Britain First’s Jayda Fransen, who was recently convicted for religiously aggravated harassment of a woman in a hijab, is as dangerous as it is despicable.

And his erratic tweeting last night, in which he publicly rebuked Theresa May for having criticised him, was not just an insult to her, the like of which no British Prime Minister has received from a US President in modern history. It was an insult to the United Kingdom.

This is not the first time his thuggery has reached our shores. After the attacks on Borough Market and London Bridge in July he launched an extraordinary attack on Sadiq Khan, tweeting: “At least 7 dead and 48 wounded in terror attack and Mayor of London says there is ‘no reason to be alarmed’!” The reality, that Khan had in fact been advising the public not to be alarmed by the increased police presence, was apparently a “pathetic excuse”.

The fact that Trump’s tweets today are so unsurprising does not make them any less shocking or disturbing. Britain First are fascists, plain and simple. If further proof were needed that Donald Trump is no friend of Britain, it is now plastered across his Twitter feed.

This should serve as a wake-up call to us all, because Brexit has created a fundamental choice about the kind of country we want to be. Are we with Europe, or with Trump? Do we want to leave behind the European model of high social, health and welfare standards in order to embrace the deregulated, low-welfare US model?

The likes of Liam Fox, Boris Johnson and Daniel Hannan have always seen Brexit as a pre-text for pursuing the latter. But they were smart enough to know that they couldn’t tell voters that, because such an agenda could not carry the support of the vast majority of the British public. With the election of Trump it immediately became even less appealing.

And yet, with the government’s decision to leave the single market and customs union, it is now happening. Ties with Europe are being severed to pave the way for a trade deal with an “America First” United States. This is a mistake, both geopolitically and economically.

Given that tariffs between Britain and US are already low, a quick deal that only addresses tariffs will bring only marginal benefits. So, the real battle will be over rules and regulations. And it is clear who will have the whip hand.

Speaking in London earlier this month, US commerce secretary Wilbur Ros made clear that a trade deal will mean lowering UK food standards and accepting the importation of chlorinated chicken, GM crops and hormone-injected beef. Doing so, of course, would make a close and frictionless trade relationship between Britain and the EU impossible.

Having belatedly realised how difficult and one-sided a deal on goods and agriculture will be, Fox has begun talking about wanting to negotiate a deal in services. But it is implausible that the US would go along with a deal that covered only services.

After years of negotiations, whatever deal emerges would then have to go through Congress, where lobbyists will pick through it line by line, slowing it down and fighting to protect their own interests. Theresa May’s refusal to rule out opening up our NHS to competition, something American pharmaceutical companies will be clamoring for, should have set alarm bells ringing.

Trump sees international trade as a game of winner-takes-all. It is a great irony that the free trade fantasists driving the government’s Brexit policy have now placed all their eggs in the basket of the most protectionist US president of modern times – a man who far from signing free trade agreements has set about dismantling them, from the Trans-Pacific Partnership to NAFTA.

To compound matters, the government’s courting of him has weakened our negotiating position in Brussels. Boris Johnson’s jibe last year that EU leaders should “snap out of their collective whinge-o-rama” over Trump got things off to a bad start. And when Theresa May invited the President for a state visit to the UK just days after he came to office, and repeatedly refusing to condemn the President’s disgraceful travel ban, she demeaned herself and weakened her standing in Europe.

So when Emmanuel Macron later said “Britain is becoming a vassal state… the junior partner of the United States”, he did not intend it as a compliment (though that is no doubt how the likes of Fox and Johnson interpreted it). And when Michel Barnier expressed concern recently that Britain is flirting with “less environmental, sanitary, food but also probably financial, taxation and social regulation” he was making an important point. Britain cannot have two mutually incompatible sets of standards.

Few believed they were voting back in June 2016 for lower standards. And nobody voted for us to ally ourselves with a US President who supports far-right movements and attacks the British Prime Minister for daring to express disapproval. It is clear that that the offer of a state visit should be withdrawn

But assuming Trump visits Britain on a “working visit” early next year, as currently planned, how will we respond? It is clear that we now face an era-defining choice, between a future hand in hand with Trump, or a genuinely “special relationship” with our European friends. It is not too late for us to change course.

Francis Grove-White is the deputy director of Open Britain