Just over a year ago, in her new year message, Theresa May promised to use 2018 to maintain what she said had been the steady progress towards Brexit achieved during the previous 12 months. Delivering on the referendum result in a sensible way was, she claimed, what both Leavers and Remainers clearly wanted her to do. “Whichever way you voted in the referendum, most people just want us to get on and deliver a good Brexit, and that is exactly what we will be doing,” she said from the cabinet room inside 10 Downing Street.

Since then May has lost one foreign secretary, two Brexit secretaries, and six other government ministers over Brexit. The past year has not been one of steady progress but of constant and unremitting crisis. As 2018 draws to its close, Theresa May’s tortuously negotiated and hugely unpopular Brexit deal with the EU cannot even be put to a vote in parliament because the government knows MPs will throw it out. Parliament is gridlocked. No majority exists for May’s Brexit deal, or indeed any other kind of Brexit that anyone can think of, including no deal.

The Tory party is at war with itself, as is Labour, over how and, increasingly, whether we should now leave the EU at all. Businesses are in despair because, with less than 100 days to go before we depart from the world’s largest trading bloc and single market, no one can tell them what the new rules under which they will soon have to operate will be. Today the British Chambers of Commerce says the “no deal” outcome it increasingly fears would mean “chaos for firms on any number of fronts including customs, tariffs, disorder in their supply chains, and recognition of qualifications”. Its director general, Adam Marshall, says current “lack of clarity” is already forcing firms to make “tough business judgements … such as opening warehouses and distribution hubs on the continent, applying to European regulators and setting up legal identities – this means that jobs and investment intended for the UK are being diverted out.”

Economic growth is slowing and the stock market has fallen over 1,000 points since the middle of the year. Increasingly people are beginning to wonder whether the “good Brexit” that the prime minister promised a year ago can be delivered at all. At the start of the year the idea of a second referendum was not talked about seriously by more than a few MPs, and had little support among the public at large. Today, however, amid the chaos, going back to the people to ask them what to do is seen by many more as a possible way out of the impasse, and even by some senior Conservatives as May’s best option for getting her deal through. A second vote is under active discussion inside 10 Downing Street, although this is offically denied. So, too, is the possibility of asking the EU for permission to delay Brexit until July – putting back the article 50 timetable so we can find a way out of the mess.

The prime minister now intends to hold the much delayed “meaningful vote” on her deal in mid-January, and in the meantime to try to wring enough concessions and clarifications out of the EU over the Irish backstop to convince the Democratic Unionists and more of her own MPs to back her. The EU, away on its Christmas and New Year holiday for the next fortnight, does not, however, appear overly keen to move at all on matters of substance. Despite this, ministers still hope that by holding the vote so close to the 21 January deadline for doing a deal, laid down in the European Union (Withdrawal Act) 2018, they will be able to focus minds.

The option the government will present will be between May’s deal and no deal, between leaving with a two-year transition and falling off the cliff into World Trade Organisation rules, or no Brexit at all. Downing Street also hopes to be able win over some Labour MPs in leave-supporting seats whose constituents want to see Brexit delivered.

Divisions in Jeremy Corbyn’s party over Brexit make it even more difficult to predict what will happen in the next three months. Were Corbyn himself to be an enthusiastic backer of a second referendum, then another public vote could well win the approval of a majority of MPs in parliament. But the Labour leader, a lifelong Eurosceptic, appears hugely reluctant to back a second vote, despite the fact that the party agreed at its annual conference in Liverpool in September that one should become an option if it could not force a general election. Yesterday there was a ferocious backlash against Corbyn from Remain-backing party supporters after the Labour chief gave an interview to the Guardian in which he suggested that Brexit would go ahead even if Labour were to win a snap election. In other words, he seemed not to want to try to stop the UK from leaving – although most Labour supporters would be delighted if the UK remained. With less than three months to go until the UK is due to leave, it is not just the all too evident divisions within the Tory party that are preventing a Brexit solution from coming into view, but the increasingly wide ones that exist in Labour, too.