Donald Trump just enjoyed a very successful trip to France.

New president Emmanuel Macron gave him the full red carpet treatment in Paris to celebrate Bastille Day.

They and their wives dined together at the Eiffel Tower, watched their two militaries put on a wonderful show, and spoke very highly of each other’s countries.

But President Trump didn’t come to Britain.

Donald Trump just enjoyed a very successful trip to France where he got the full red carpet treatment from President Macron. But President Trump didn’t come to Britain and isn't planning to any time soon

Nor is he planning on coming any time soon, despite being half-British.

Of course, he should have done so by now.

Prime Minister Theresa May invited him in January to visit the UK with a formal state visit, hosted by The Queen.

But the trip was postponed several times amid outrage from liberal anti-Trump haters and now it’s been put off until next year, if it happens at all. President Trump told Mrs May in a phone call last week that he does not want to go ahead with the visit until he is confident he won’t be met with mass protests and blind fury.

I don’t blame him.

Who would go to their best friend’s house for dinner if they knew the other guests were going to spend the entire time screaming abuse at them?

Trump’s most vocal and powerful British opponent is Sadiq Khan, the Mayor of London.

He told CNN yesterday: ‘State visits are different from a normal visit and at a time when the President of the United States has policies that many in our country disagree with, I am not sure it is appropriate for our government to roll out the red carpet. If you somehow think it is not possible to be a Muslim and a proud westerner, I am happy to disabuse you of that idea, whether you are a reporter for CNN or Donald Trump.’

This is the latest in a series of public statements the Mayor has made attacking the US President in a bitter war of words.

Khan clearly sees himself as something of a people’s hero with this behaviour; a Robin Hood like character fearlessly standing up to the big bad Sheriff of Nottingham from across the pond.

And why would he come to Britain, despite Theresa May inviting him earlier this year, when his most vocal and powerful British opponent is Sadiq Khan, the Mayor of London?

Yet like so many on the left who’ve been calling for Trump’s state visit to be cancelled, Khan’s also a shameless hypocrite.

Britain has rolled out the red carpet for all manner of despots and tyrants in modern times, from Putin to Assad and Middle Eastern leaders like the King of Saudi Arabia and the Emir of Kuwait.

I don’t recall seeing Sadiq Khan leading any furious protests to stop THOSE visits happening.

But he apparently views Donald Trump as worse than any of them, a man worthy of special vindictive attention.

I get why Khan, the first Muslim to run Britain’s capital city, remains unhappy about what Trump said initially about a US Muslim ban back in 2015.

Trump said he wanted to give America time to ‘figure out what’s going on’ with regard to Islamist terrorism following an appalling attack that killed 20 people in San Bernardino, California.

It was an absurd thing to suggest, as I wrote at the time, and he shouldn’t have done it.

But Trump dropped that inflammatory suggestion after he became President and he should be judged on his actions now he is occupying the White House, not what he said during an election campaign.

What is undeniable is that Trump’s primary motivation was the very real and serious threat posed by Islamic State.

And frankly, after two horrendous ISIS terror attacks in London in the past few months – and another at an Ariana Grande concert in Manchester - Sadiq Khan might be well advised to get off his high horse and start working WITH Trump to see how more can best be avoided.

It is perfectly possible, as President Macron and Germany’s Chancellor Merkel have shown, to disagree with Trump both privately and publicly about issues but still afford him the respect that the leader of the free world commands.

They put their national interest over any personal feelings because they realise that in these dangerous and unpredictable times, it is far better to have America onside than offside.

But this is something the likes of Sadiq Khan either refuse to understand or choose to deliberately ignore.

By continuing to insult and lecture Trump, and repeat his call for the state visit to be scrapped, Khan is being bloody stupid and causing enormous potential damage to Britain.

Let me explain why:

It’s just 18 months until Britain leaves the European Union - a decision that looks more and more reckless with every passing day.

If those who voted for Brexit (full disclosure: I voted Remain) knew then what they know about the cold, hard reality of such a seismic split, I very much doubt many of them would vote the same way.

But we are where we are and we now have to make it work.

The single best way we can protect ourselves against the economic Armageddon many are predicting when we leave the huge EU single market is to do some very speedy and lucrative trade deals with countries outside the EU.

Our biggest non-EU trading partner is the United States and we desperately need that trading agreement to be stronger than ever.

The single best way we can protect ourselves against economic Armageddon is to do some very speedy and lucrative trade deals with countries outside the EU - and the biggest non-EU trading partner is the United States. Being nice to Trump is in our country's best interest

A week ago, when he met with Theresa May at the G20 summit in Hamburg, President Trump promised to sign a new trade deal with Britain ‘very, very quickly.’

He said: ‘We will do a very big deal, a very powerful deal. Trade will be a big factor between our two countries.’

Then he added: ‘There is no country that could possibly be closer than our countries.’

Britons should have punched the air with joy when they heard this.

Trump, despite all the abuse we’ve given him, is still, incredibly, minded to help us out financially and still considers us America’s No1 ally.

But rather than feel grateful, Britain’s shrieking anti-Trump brigade have once again raced to attack him, led by Sadiq Khan.

The Mayor’s behaviour is pathetically graceless, utterly self-defeating and way above his pay grade.

Khan does not run Britain. Theresa May does.

And if she, and Her Majesty the Queen, have invited the US president to enjoy a state visit, then that’s exactly what he should enjoy.

Frankly, a gold royal carriage trip down Pall Mall and a game of golf at Windsor Castle seems the very least we can do by way of gratitude for a hefty new UK-US trade deal.

So my message to petty little pipsqueak Sadiq Khan is simple: shut up.

Save all the energy you’re currently expending on grand-standing against Donald Trump and refocus it on keeping London safe from further terror attacks and tower block fires.

Because the reality is that when you insult the President of the United States, you insult America – our greatest and most reliable ally.

And that, trust me Mr Mayor, is a very, very dumb thing for any senior politician in Britain to be doing right now as we charge over the cliff into an unknown post-European existence.

Clamber down from your hypocritical high horse, hold your hectoring nose, and stick a cork in that incendiary mouth of yours.