Small, brightly coloured and full of song, the yellowhammer splits opinion in the ornithological world. The RSPB, Britain’s foremost bird protection group, says the fluorescent flyer is ‘at risk’ and in need of urgent action. But ask the IUCN, a global equivalent, and they’ll tell you the species is of ‘least concern’. Fitting then that ‘Operation Yellowhammer’ – the UK’s no-deal Brexit assessment – is proving fiercely divisive. The leaked government dossier hints at nationwide meltdown if an agreement isn’t struck, sparking new calls to wrest control from Downing Street and force no-deal off the table.

Even in these heady political times, the Yellowhammer leak was utterly sensational. Outlining potential chaos awaiting a no-deal Britain, the incendiary documents leave little to the imagination: disruption at the ports, border issues with Ireland, shortages of food and medicine, nationwide protests. The study is outdated, government ministers insist, but its findings speak to a mounting fear of no-deal Brexit.

Britain’s prime minister, Boris Johnson, is hopeful of a new accord with Brussels, but he’s adamant the UK will leave on October 31 come what may. This ‘do or die’ approach hits all the right notes with Brexit’s most stalwart backers. But for a majority of British MPs, Johnson’s posturing is at best dangerous brinkmanship – and at worst a wilful flirtation with catastrophe. “All credible economic analysis shows that the losses will far exceed the potential benefits,” said former Chancellor Philip Hammond recently. He and like-minded Conservatives are clear in their message to the prime minister: don’t let no-deal happen.

There hasn’t been the slightest sign of compromise, however, with both sides refusing to budge on the so-called Irish backstop. Any Brexit agreement hangs on this clause, a last-resort mechanism that prevents a hard border on the island of Ireland by keeping parts of the UK aligned with EU rules. It’s anti-democratic, says Boris, slamming Brussels’ refusal to discuss an alternative. Europe has less to lose than Britain, claim EU bosses, who seem confident that London will capitulate.

But not all are willing to play the no-deal waiting game. Labour leader Jeremy Corbyn has issued a cross-party plea to back him as prime minister, allowing for a Brexit-day delay while a new agreement is struck. There are enough no-deal opposing MPs to defeat Mr Johnson in a confidence vote, Corbyn believes, but knows his hard-Left credentials will give many pause. To placate fears, he has insisted his premiership would be temporary – just long enough to postpone the October 31 Brexit deadline before calling an election.

Vociferous as they are in opposing no-deal, Corbyn’s would-be backers aren’t convinced. While he’s won over the Scottish and Welsh nationalists, the Liberal Democrats and pro-EU Conservatives – whose votes he desperately needs – don’t want to align with such a polarising figure. Liberal Democrat leader Jo Swinson rubbished the plans as “nonsense”, while Dominic Grieve, an influential anti-Brexit Tory MP, rebuked Corbyn as the “most unlikely way forward”.

Part of the issue lies in the ambiguity of the Labour man’s plan, experts believe. “He offers the aim of calling a general election but not the certainty of doing so, nor does he say when,” notes Bronwen Maddox of the Institute for Government, a think tank. “He does not say how long an extension he would ask the EU for (and presumes that one would be given, a likelihood but not a certainty). He does not say what powers he would have as prime minister or what powers others in this pact would have”.

Substituting Mr Corbyn for a less divisive character has been suggested, with Ken Clarke and Harriet Harman – veterans of parliament – earmarked as potential candidates. But even amid the madness of Brexit, the sudden ascendancy of two longtime backbenchers seems far fetched. Even still, Mr Johnson will be wary of the development – Jeremy Corbyn may be too toxic to garner support, but a more widely respected figure could make the arithmetic work.

Time is on the prime minister’s side, however, with just ten weeks for his opponents to orchestrate and execute their coup. A vote of no confidence, the ensuing period of government building, entry into No 10, formal talks with the EU to delay Brexit – these don’t happen in a blink of an eye. And while other strategies to prevent no-deal have been floated – achieving a two-thirds majority to call an election prior to Brexit, or seizing control of parliamentary business through legislative means – these are equally uncertain to deliver.

But not all is lost for opponents of no-deal. As poorly received as they were, Mr Corbyn’s proposals aren’t quite dead in the water. Swinson, Grieve and others he’s yet to convince have agreed to speak with the Labour leader. As October 31 draws closer, these key players – politicians who’ve staked their careers on blocking Brexit – are likely to become more pliant. This will play heavily on Prime Minister Johnson’s mind. But if he’s sincere in his no-deal pledge, time matters little: the man who intends not to blink needn’t worry about the clock. The fortunes of the little yellowhammer are hotly disputed – Britain’s future isn’t much clearer.