BORIS JOHNSON seems to be leading a government that subscribes to his key principle, that if you say something with sufficient confidence you can make it come true, even if the facts suggest otherwise.

This is the case over much to do with Brexit and in particular a trade deal with the EU-27.

Back in 2016, at the time of the referendum, he claimed this would be the quickest and easiest trade deal in history. The EU would do whatever was necessary to allow the UK to enjoy the membership terms of the customs union, while doing deals outside it. This was never going to work, but the same mantra is still being repeated.

That, no doubt, is why Johnson was persuaded to set a timetable of the end of the year for a deal. In doing so he made the mistake of believing his own publicity.

Pumping billions this week into a railway to benefit England, Johnson has moved on from Brexit. He insists a trade deal will be easy, even if we refuse to align with EU-27 standards. We have moved from unfettered or frictionless trade to a deal based around the arrangements for Canada, which in EU terms is a specialist player and market.

If that does not work out, Johnson has suggested an Australia style deal – but there is a fatal flaw in that, because the EU does not have a meaningful trade agreement with Australia.

The original promise of no border checks has been forgotten. Now we will even have border checks on goods moving between Northern Ireland and the rest of the UK. This is to protect the border between Ulster and the EU. This was always going to be an issue. Frictionless trade outside a customs union is impossible. It is described as a customs union because standards are harmonised to allow open trading. This is not the situation between the EU and Canada, or indeed with any other country outside the EU-27.

Cold water was poured on Johnson's 'it will be alright on the night' approach this week. This came from Michael Gove, who will play a key role in the negotiations with Brussels. He said that as the UK would be outside the single market and customs union, regulatory checks at borders would be inevitable.

This, the food industry warned, could lead to shortages on supermarket shelves. This might create opportunities for UK suppliers to replace imports, but that would be a limited gain. The food market is complex and the UK needs to both export and import for the equation to balance. That said, Gove deserves some credit for honesty and bubble bursting.

Before the negotiations get going, the UK needs to accept it is the one looking for a unique deal. It does not bring a lot to the table, even if it is an important market for some EU-27 business, not least in Ireland. The EU is the world's biggest trader in food and agriculture products; it has seen and continues to see massive year-on-year growth each month.

This is not just about exports – it carries clout as a big importer, for example being the number one soya market for the United States. Trade is about scale and the EU-27 has that. It has free trade deals with many countries on the UK's target list and if it fights dirty to block the UK, for example with Japan, it has the muscle to win. As a former member state, the UK needs the EU-27 as a global trade ally and not as a competitor.

The new European Commission president, Ursula von der Leyen, is a lot more difficult to denigrate than her predecessor, Jean Claude Juncker. Like Johnson, she was brought up in Brussels as the child of a diplomat, but had a more glittering academic career as a doctor and lawyer. She has the potential to get under his thin skin, and she did so this week in the European parliament.

She scoffed at his approach to trade – not least the suggestion that if the UK cannot have a Canada style deal it will opt for the Australian model. Acidly, she pointed out that Australia has no current deal with the EU and trades largely on World Trade Organisation terms. It is not a perfect analogy – but Mrs von der Leyen seems to have been cast in the role of the little boy pointing out the emperor's nakedness.