The visitors from abroad who have addressed both Houses of Parliament from Westminster Hall are: Albert Lebrun, Charles De Gaulle, Nelson Mandela, Pope Benedict XVI, Aung San Suu Kyi…and Barack Obama.  Any decision about whether Donald Trump should follow in their footsteps will be taken not by the Government, but by the speakers of the two houses.  John Bercow can be relied upon to ensure that the President doesn’t speak from beneath that famous hammer-beam roof, but is shunted off to another part of the building, presumably the Royal Gallery.  Trump will seethe at having closed to him what was open to Obama.

But this is far from being the only indignity that will be heaped on his shoulders.  A petition urging that the President not be invited to make a state visit “because it would cause embarrassment to her Majesty the Queen” has smashed through the 100,000 ceiling it needs to be debated in Parliament, and is soaring up, up and away towards a million signatures.  Ruth Davidson believes that the visit “could not possibly occur in the best traditions of the enterprise while a cruel and divisive policy which discriminates against citizens of the host nation are in place”.  Alistair Burt has said that there should be a “joint decision” to delay the visit.

Debates about Trump in the Commons have form.  One took place a year ago – in Westminster Hall, as it happens – on banning him from Britain. (What goes around comes around.)  Most of the MPs present did not support a bar, but the session was a carnival of Trump-bashing.  A debate on the new petition would doubtless display less contempt and more alarm, but its form might not permit a vote on a motion.  A separate backbench business debate, however, would allow for a division. Sources that ConservativeHome spoke to yesterday said that such a debate is possible before the half-term recess.  However, the Government has a history of turning a blind eye to such votes.

It would find it more difficult to ignore the result of an Opposition Day Motion.  Jeremy Corbyn’s call for the state visit to be cancelled is, more by luck than planning, perhaps his best-yet tactical gambit.  Tory MPs were queueing up yesterday to complain about the President’s banning order.  Beside Burt, we counted James Cleverly, Nusrat Ghani, Anna Soubry, Paul Scully and, significantly, Sajid Javid.  Were Corbyn to follow up his words yesterday with an Opposition Day debate in due course, it is hard to imagine Conservative MPs trooping through the lobbies with him.  But in the present volatile atmosphere one cannot be sure. Labour may take this route after half-term.

The main difficulty for Theresa May comes if British citizens are caught up in the ban: there are some 250,000 people who have dual British nationality and were born in Iraq, Iran or Somalia.  This problem seems – for the moment, anyway – to be solved (though both the drawing up and implementation of the order, with a ban on some green card holders being first implemented and then withdrawn, has been so chaotic than anything could happen yet).  One reading of yesterday evening’s clarification about the status of British dual citizens is that it shows the influence Theresa May has in the White House.

Another is that it demonstrates a wider attempt by the new administration to bring some order to a policy whose design was reportedly carried out without consultation with the Justice Department, the State Department, or the Department of Defense.  National Security Council lawyers may have been prevented from evaluating it.  It is also claimed that that Customs and Border Protection and U.S. Citizen and Immigration Services, the agencies tasked with carrying out the policy, were briefed very late – while Trump was actually signing the order itself.  (Its key part, for those who want to read it in full, is section 3c.)

Where does all this leave the state visit? Very simply, if the President of China – who heads a government infinitely more noxious than Trump’s – can make one, then so should the President.  There were few protests and petitions before Xi Jinping addressed Parliamentarians in the Royal Gallery less than eighteen months, ago.  The contrast between the noise now and the silence then is a classic illustration of left-wing infantilism.  Protests at the horror of what happens in China – in particular, its forced organ harvesting – have largely been confined to a small band of Christians, represented on this site at the time by Fiona Bruce, Fiona Hodgson and Benedict Rogers.

But neither Trump’s concession to Britain nor the question of double standards are likely to deter some MPs.  The bottom line is that he promised a Muslim ban during his campaign, and has crafted a policy that effectively delivers one – however limited, inconsistent, ineffective and damaging to America’s interests it may be.  His priority is to send a signal to those who voted for him that he is delivering the bar he promised, and never mind what the rest of the world thinks.  But if he doesn’t care what it thinks, he can’t complain when it kicks up rough.  This is shaping up to be an unhappy visit. Problems with the Prince of Wales over climate change are only the overture.

The Prime Minister will be hoping that yesterday evening’s clarification draws the sting from the protests.  The Government’s line is taking shape roughly as follows: “Look, we don’t approve of this ban – and have said so.  But we have at least ensured that it doesn’t cover British citizens.  And, remember, these are temporary measures.  There is unlikely to be any blanket ban on anyone come the summer.  Trump is likely simply to toughen up the visa regime that Obama left him.  Let’s wait and see what happens.  Anyway, we need this guy for trade and Brexit.”  It will persuade most Tory MPs, but how big will the dissenting minority be?