Donald Trump should never have been offered a state visit to the UK seven days after being inaugurated as President of the United States. As Lord Ricketts, former head of the UK Foreign Office, pointed out this morning, it is unprecedented for a president to receive this honour in the first year of office. (Barack Obama and George W. Bush were both in the third year of their presidencies when they were invited on their first state visits.) Lord Ricketts called the invitation “premature”, and noted that Trump could come to Britain on an official visit and meet the Queen, without the full pomp and ceremony of a state visit.

He is probably right – an official (but not “state”) visit and tea with the Queen would have been a far less controversial option. But for whatever reason, Theresa May decided to go big(ly). Maybe Trump pressured her in their meeting last week, nagging her about when he would get to go to Buckingham Palace. Maybe she was conscious that she was the first foreign leader to meet the new president, and wanted to reciprocate the gesture. Or maybe she just made the calculation that anything that could help ram though a quick and beneficial trade deal would get the Brexit hounds off her back, and was therefore worth it. So the invitation was made, protocol and precedent be damned.

Then Trump signed an executive order banning travellers from seven mostly Muslim countries from entering the US and putting the travel rights of Green Card holders and dual British nationals at risk. May is currently under pressure to reveal if she was briefed about the intended order when she met the president – but if she was, she clearly decided the calculation was still worth it. 1.7 million Brits disagree, however, and thousands took to the streets across the country last night to make their feelings on this gesture of friendship known. “Donald Trump’s well documented misogyny and vulgarity disqualifies him from being received by Her Majesty the Queen or the Prince of Wales”, reads the petition.

Some have pointed out that during her 65-year reign, Queen Elizabeth II has met her fair share of controversial rulers. Bashar al-Assad of Syria, for example, in 2002. Before that, in 1994, Robert Mugabe of Zimbabwe (when he was awarded an honorary knighthood). And of course, the full state visit for Romania’s Communist despot Nicolae Ceausescu in 1978. The Queen can handle Trump. The question is therefore what would Theresa May’s government rather risk: its fledgling relationship with the leader of the free world, or its global reputation as a leading nation that stands up for decency and human rights?

It’s not an attractive set of options, so here’s a third alternative for Theresa May. Let the invitation stand, invite Trump to dinner at Buckingham Palace, and lay on the full state visit treatment. But explain to the White House team that there is a way we do things here in Britain, and as an honoured guest, the president is expected to respect it. No picking and choosing which members of the royal family he gets to interact with – the Prince of Wales will be the King of Great Britain within ten years or so, and meeting with him is an integral part of any state visit. If Charles wants to talk about climate change, that is his right as a host. Trump is apparently uncomfortable about getting “lectured” at by Prince Charles – he should get used to it. Not all foreign leaders or heads of state are going to tiptoe around him for four years, and he has a duty as America’s leader to be respectful and gracious.

Also, he should accept that Britain has a robust free press and a lively tradition of protests. There will be demonstrations in London over Trump’s incendiary rhetoric and aggressive immigration policies, and these are not going to be shut down or hindered just because the president might get a bit embarrassed. Equally, we have our own journalists, and they are allowed to ask the tough questions Trump prefers to dodge. You need only watch the video of Trump refusing to answer BBC Political Editor Laura Kuenssberg’s question last week and threatening to call off the whole UK-US relationship to see how uncomfortable he is with this. He is a populist who wants to be universally adored and feted as the saviour of both America and the world. A few days in London, surrounded by activists protesting his very existence and forced under the harsh glare of the British media without the giddying spin of Sean Spicer and Kellyanne Conway to defend him, might give him a reality check.

As for Theresa May, she should calmly welcome Trump’s team, but make it clear that the protests, the press, and Prince Charles are not up for negotiation. If President Trump wants to come to Britain, he needs to play by British rules.