Brexit was the dog that didn’t bark in Theresa May’s reshuffle this week. The prime minister did not move any cabinet minister with frontline Brexit responsibilities. Nor did she even attempt to. The pro-Brexit trio of David Davis, Boris Johnson and Michael Gove all remained in post, as did Philip Hammond and Amber Rudd from the pro-European side. David Lidington’s promotion gave Mrs May a pro-European consigliere to replace the pro-European Damian Green. In broad essentials the Brexit balance is unchanged.

Indeed if the reshuffle had a coherent original purpose it was specifically not to do with Brexit at all. The shake-up was supposed to signal that this government has goals other than Brexit, mainly bread-and-butter domestic ones that may attract hard-pressed voters – for example in health, education and housing – and that there are new ministers ready, willing and able to reach them.

In the event, the reshuffle was a botched job, which has drawn attention to Mrs May’s weaknesses and not her strengths, real or imagined. It was a surprise that Jeremy Corbyn did not make more of this weakness in the first prime minister’s questions of the new year on Wednesday. Yet a political killer instinct of that sort is not the Labour leader’s style. He preferred to attack the state of the National Health Service – understandably in many ways, of course, since the health crisis is profound and it is rising fast up the list of the public’s concerns.

Quick guide What are Brexit options now? Four scenarios Show Hide Staying in the single market and customs union The UK could sign up to all the EU’s rules and regulations, staying in the single market – which provides free movement of goods, services and people – and the customs union, in which EU members agree tariffs on external states. Freedom of movement would continue and the UK would keep paying into the Brussels pot. We would continue to have unfettered access to EU trade, but the pledge to “take back control” of laws, borders and money would not have been fulfilled. This is an unlikely outcome and one that may be possible only by reversing the Brexit decision, after a second referendum or election. The Norway model Britain could follow Norway, which is in the single market, is subject to freedom of movement rules and pays a fee to Brussels – but is outside the customs union. That combination would tie Britain to EU regulations but allow it to sign trade deals of its own. A “Norway-minus” deal is more likely. That would see the UK leave the single market and customs union and end free movement of people. But Britain would align its rules and regulations with Brussels, hoping this would allow a greater degree of market access. The UK would still be subject to EU rules. The Canada deal A comprehensive trade deal like the one handed to Canada would help British traders, as it would lower or eliminate tariffs. But there would be little on offer for the UK services industry. It is a bad outcome for financial services. Such a deal would leave Britain free to diverge from EU rules and regulations but that in turn would lead to border checks and the rise of other “non-tariff barriers” to trade. It would leave Britain free to forge new trade deals with other nations. Many in Brussels see this as a likely outcome, based on Theresa May’s direction so far. No deal Britain leaves with no trade deal, meaning that all trade is governed by World Trade Organization rules. Tariffs would be high, queues at the border long and the Irish border issue severe. In the short term, British aircraft might be unable to fly to some European destinations. The UK would quickly need to establish bilateral agreements to deal with the consequences, but the country would be free to take whatever future direction it wishes. It may need to deregulate to attract international business – a very different future and a lot of disruption.

Just as the non-barking dog is the key fact in the Sherlock Holmes story, so the absence of Brexit is the key deceit in the reshuffle. This government will be judged on many things, but it will stand or fall in 2018 by its handling of the Brexit talks. The fact that Mrs May did not use the reshuffle to push more determinedly towards her preferred Brexit outcome is an eloquent fact. It proclaims one of two things: either that she still does not know her preferred course; or that she is too weak to enforce it within her divided party and government. Quite possibly it proclaims both of these things together.

The consequence is that 2018 is beginning as 2017 ended – with ministers pretending to themselves and to the public that much more is in play over Brexit than is in fact the case. Yet the completion of phase one of the Brexit talks last month involved large choices by Mrs May whose significance has still not been fully understood. In particular, by agreeing that the Irish border will remain soft – and accepting that this agreement will be binding – she has chosen to take Britain down a path that could, and should, lead to a soft Brexit.

Politically, Mrs May is reluctant to spell this out, and even to face it herself. Perhaps that will change when she makes her next keynote speech on Brexit, possibly next month. If she does, however, it would be a break with all her past practice. Experience says she will use her own form of Brexit doublespeak for as long as she can get away with it. She will pretend that the agreement she hopes for this year will be a detailed deal (no chance), that the subsequent transition period is for implementation (it is for negotiation) and that the UK will leave the single market and customs union for good, while retaining all the advantages of both (dream on).

This week, ministers are still playing this same game. Mr Davis and Mr Hammond were in Germany on Wednesday trying to get a cherry-picking deal that the EU and the Germans have consistently said is not on offer. Mr Davis moans that the EU warns of the perils of a “no deal” outcome even though the UK government itself still treats this as an option. Mrs May has survived until now by pretending that Brexit is one thing when in fact it is another. In the same manner she has started 2018 by pretending that Brexit is sorted when in fact it is not. Yet be in no doubt. This is the year when the fantasy collides with the facts. This dog will both bark and bite. Neither Mrs May nor anyone else should pretend otherwise.