STEPHEN GLOVER: Be warned, Boris – if you trash the UK’s reputation, you’ll destroy your own, too 

Bear in mind with what follows that I voted Brexit in 2016, and for Boris Johnson and the Tories last December. I long for the moment that Britain truly leaves the EU.

With that said, let me express my shock that Northern Ireland Secretary Brandon Lewis should have told the Commons on Tuesday that the new Internal Market Bill could lead to the UK breaking international law in a ‘very specific and limited way’.

Forget the specific and limited business. You either break a law or you don’t. And this Government is envisaging the possibility that it might. Such an admission is unprecedented in modern times.

By and large, British governments honour their treaties and obey international law. It’s one of the things on which we pride ourselves. Less civilised nations may breach their agreements, but we don’t.

Admittedly, from time to time, British governments do bend the rules. When, in 1956, Prime Minister Anthony Eden colluded secretly with the French and Israelis to invade Egypt after its nationalisation of the Suez Canal, he broke international law.

And before Tony Blair took us to war against Iraq in 2003, he leant on the Attorney General, Lord Goldsmith, to reverse his previous judgment that invasion would be illegal under international law.

Note that whenever governments have flouted the law in the past, they have either kept quiet about it, or pretended that what they were doing was perfectly lawful.

Not so Brandon Lewis. He was brazen and shameless. Cheerful, too. He might have been announcing an insignificant, but positive development in the province for which he is responsible. Oh, by the way, we may go ahead and break international law.

Was he going out on a limb? Exceeding his brief? That, for a moment, was my vain hope. But neither the Prime Minister nor any senior minister has rapped Mr Lewis’s knuckles, or said he wasn’t conveying the Government’s true position. He clearly was.

That is why Sir Jonathan Jones, the Government’s most senior lawyer, resigned on Tuesday. It was a momentous event. This eminent legal adviser will rightly not condone tearing up any part of an international agreement.

How has it happened that the British Government is preparing to override bits of the Withdrawal Agreement —the treaty it signed with the EU last January — which set out the terms for our leaving the organisation?

The truth is that, in an understandable rush to conclude a deal and meet his deadline of January 31, Boris Johnson characteristically didn’t bother with the fine print. Although he denied placing a border in the Irish Sea between Britain and Ireland, this was effectively what he did.

No 10 is now conceding that the Withdrawal Agreement — endlessly described as ‘oven ready’ by Mr Johnson during last December’s General Election campaign — contained ‘ambiguities’ and lacked clarity in ‘key areas’.

The trouble is what the Government regards as a lack of clarity, the EU reasonably regards as an inviolable agreement. If we fail to do a trade deal with Brussels over the next two months, No 10 intends to introduce new legislation.

Proposals include eliminating tariffs on goods travelling from the rest of the UK to Northern Ireland, if negotiations with the EU on a free trade agreement fail. The Government would also ignore previously agreed obligations on state aid — official support for businesses — in Northern Ireland.

Such measures are, in fact, desirable. But they are at odds with the Withdrawal Agreement. They should have been negotiated before Britain signed it, though it is unlikely the EU would have agreed to them.

Once made, an international agreement can’t be legally unpicked, unless there has been a material change in circumstances, which within the space of eight months there obviously hasn’t been. Boris Johnson seems unable to grasp the sanctity of treaties. They can’t be torn up and discarded like old columns.

Former PM Theresa May put it well on Tuesday when she asked rhetorically: ‘How can the Government reassure future international partners that the UK can be trusted to abide by the legal obligations of the agreements it signs?’

And although I am far from being a fan of ex-prime minister Sir John Major, I’m afraid the statement he issued yesterday is correct. ‘If we lose our reputation for honouring the promises we make, we will have lost something beyond price that may never be regained.’

None of this is to deny that the EU’s chief negotiator, Michel Barnier, has behaved in an infuriatingly intransigent manner during talks with his opposite number, David Frost. Brussels is incapable of accepting that, when it finally extricates itself from the EU, Britain will again be an independent nation.

Nowhere is this clearer than in negotiations over fishing, where the EU has demanded unfettered access as though nothing has changed. Mr Barnier recently made the nonsensical statement that Britain ‘will recover the full sovereignty’ of its waters but not necessarily of the fish in them.

On state aid, too, Brussels is being unreasonable in dictating that the UK should go on observing EU rules. Such terms have never been forced on a partner in any other trade deal made by the EU.

That said, given that the UK has historically dispensed much less state aid than either Germany or France, one wonders why the Government is so exercised. I think it is because it can’t bear being in the continuing thrall of the EU in the smallest degree, even if the actual issue is a slight one.

So, yes, the EU has been pretty bloody-minded. All the same, I believe the contention of some Brexiteers that the Withdrawal Agreement can legitimately be reopened, because Brussels has shown such bad faith in negotiations, is flaky.

Let’s hope an agreement is reached. I still think — just —that it will be. But if it isn’t, Boris Johnson and his pugilistic adviser Dominic Cummings (who is surely the main mind behind the Internal Market Bill) mustn’t ruin this country’s reputation for probity.

We’re not a rogue state. We’re not like China, which has been rightly accused of subverting the treaty signed with the UK guaranteeing the rights of the people of Hong Kong for 50 years from 1997.

Unilaterally re-writing parts of an international agreement would confirm the prejudices of Boris Johnson’s growing band of critics — not a few of them in his own party — who believe he has long had a contingent relationship with the truth in every aspect of his life.

Until now, I have defended the Prime Minister in my mind against charges that he is a British version of Donald Trump. Isn’t he both much cleverer and far more decent than the narcissistic American President? And yet ripping up a treaty is exactly the sort of thing Trump would do.

Maybe Johnson and Cummings are just trying to convince EU leaders they are tough, and mean business. Perhaps they realise that, in any case, getting this Bill past a growing number of restive Tories would be uphill work.

It may well never happen. But if it does, Boris should be aware that, in trashing this country’s reputation for reliability and trustworthiness, he will also destroy his own.