WE HAVE all watched films where we just know there will be disastrous consequences if someone enters a creepy house – or even worse, goes down into the cellar.

The government in London's approach to Brexit is now a bit like watching one of those films. Like the hero, its confidence is high, but it is doing things that could snatch economic defeat from the jaws of victory.

It is now a given that come the end of this month, we will no longer be members of the EU. British MEPs will have to find alternative jobs, although for many a nice pay off will ease the pain.

That will mean Boris Johnson has delivered on what he promised when elected. The combination of that, a massive parliamentary majority and increasing poll approval ratings should allow him to be relaxed about the next steps. The number one step is to secure a workable trade deal with the EU-27, but with many of his actions he is making that more difficult.

This is the arrogance that comes from such a huge majority. But arrogance does not sit well with politics and it does not make for sound decision making. At a pinch it might facilitate decisions deemed good politically, but it cannot deliver sound economic decisions or outcomes.

The first potential pitfall has been well publicised. This was the decision to limit the transition period, when the UK will continue to follow EU rules but without any official representation, to the end of the year.

The aim is to avoid a repeat of what has happened since 2016 by forcing the EU to negotiate with a gun to its head. However the delay under Theresa May was not down to Brussels, and the government must know it is setting an unrealistic timetable if it wants a good outcome from complex negotiations. Trade deals take time and that is a fact of life.

Assuming negotiations begin in March, the government is seeking a deal by the autumn, to allow time for it to be agreed by 27 national parliaments in the EU. It is also under-estimating how tough the EU trade commissioner, Phil Hogan, will be and how inexperienced UK civil servants are in the area of trade deals.

A more serious potential problem arose at the weekend when the government said it would not align UK standards with the EU. Within food and agriculture, EU standards are globally recognised for being not only high, but driven by the interests of consumers. Hogan has already questioned why British citizens would want a Brexit outcome that reduced standards, but this now seems to be what the government wants.

Its thinking may be that this will make it easier to align with the United States. If this is the case, it is an approach driven by political dogma rather than economic common sense.

All reports have shown that a trade deal with the US would offer little immediate benefit to the UK economy. That impact would be negative if a US trade deal were secured as an alternative to a good deal with the EU-27. Trade deals should not be about politics and they should not be either/or options. However if London seeks rules that will make a trade deal with the US easier, it risks losing a deal with the EU. That penny – or cent – does not seem to be dropping in London.

Johnson's powerful adviser, Dominic Cummings, firmly believes success lies in an alliance with Trump's United States. For him any trade deal with the EU would be second best and a dilution of the pure Brexit he has wanted since masterminding the leave campaign in 2016.

For agriculture, a move away from alignment with EU standards looks negative. There is little upside for farming in a trade deal with the US. Not meeting EU standards would either close us out of our nearest, biggest and best market, or would land the industry with coils of red tape to show equivalence.

Lack of alignment also raises other issues, such as product approvals for agrochemicals and veterinary drugs. The UK would have to set and implement its own rules, beginning very soon with what it will do about glyphosate when the EU product license expires in 2022.

In film terms the government is throwing open the door to the creepy house or cellar, with no idea what lies beyond or beneath.