IT would not take a clairvoyant to predict that the UK is facing the most serious rupture since the second world war in fewer than 70 days.

Here is how it might play out. By mid-March, Theresa May has successfully headed off a softer Brexit proposed by a coalition of MPs and defeated plans for second referendum by exploiting Labour divisions.

With the country hurtling towards a no-deal departure, the Prime Minister secures concessions from European partners and puts a revised deal in front of the Commons which wins over some Tory doubters.

Labour, the Liberal Democrats and the SNP oppose the new draft, but May is confident support from the Democratic Unionist Party and Tory colleagues will suffice. On the day, a hard core of Brexiteers who still have misgivings derail the plan and defeat the Prime Minister. As a result of Westminster paralysis, the UK crashes out of the European Union without a deal on March 29th.

The consequences for the UK economy and society are immediate. Excessive form-filling at ports in the south of England has led to queues of more than 15 miles in the UK and France. Farmers are panicking about the lack of seasonal harvest workers and warning about the impact of World Trade Organisation rules on exporting their products.

Hotels, pubs and restaurants are also complaining about the effect of no deal on their ability to recruit staff and shoppers staring at empty shelves in supermarkets. Car manufacturers announce plans to relocate from the UK and the financial services sector loses vital passporting rights.

But it is the strain on the NHS that is causing the most anger. The cost of medicines is to rise sharply and the Health Secretary has conceded that delays will affect the importation of life-saving drugs. All waiting times targets are suspended for five years and thousands of UK nationals in the EU are unsure if they can receive any care.

A no-deal Brexit, and the chaos many predict will ensue, is a live prospect because of the terms laid out in the Lisbon Treaty on how to leave the European Union. Once a country invokes Article 50 – the beginning of the withdrawal process – the same state has two years to negotiate a deal. The UK departs at the end of March.

However, there is wiggle room. The UK can request a temporary extension – a delay the EU would likely grant – or, as a result of a recent legal victory by Scottish politicians, unilaterally revoke Article 50 and re-start the process in the future. The exit date could be renegotiated if the political will existed.

As we reveal today, key parts of Scottish society have major reservations about the Brexit impasse and the prospect of no deal. Bodies such as the Scottish Trades Union Congress, the Scottish Council for Voluntary Organisations and the Scottish Chambers of Commerce support an extension of Article 50.

Civic Scotland is backed up by political muscle. First Minister Nicola Sturgeon, as well as Scottish Liberal Democrat leader Willie Rennie and Scottish Greens co-convener Patrick Harvie, are demanding that Brexit is delayed. Collectively these parties represent a clear majority of MSPs at Holyrood. The Prime Minister is under pressure to heed these calls.

The argument for an extension is multi-faceted. The 2016 referendum was won by Leave, but even the most passionate Brexiteer would have to concede there is nothing written in the stars about March 29. Supporters of the intervention believe it is more important to get a good deal than fixate on a specific date in the calendar.

There are also political reasons for a delay. The Leave campaign’s specific promises have been pored over, scrutinised and mocked, but eurosceptics consistently said the UK would get some form of deal from the EU. Crashing out was never part of the offer – regardless of what we have heard in recent days and weeks. An extension would not contradict the verdict delivered in the referendum.

But it is the potential economic damage that is fuelling calls for a push back. According to the Confederation of British Industry, no deal would cause GDP to shrink by up to 8% and put thousands of jobs at risk. Government analysis claimed the GDP hit could be 9.3% over 15 years. A contraction of this sort would inevitably lead to huge reductions in public spending.

Seeking an extension is within the gift of the House of Commons. Senior Labour figures seem broadly sympathetic and the Prime Minister has pointedly refused to rule out a delay.

However, as with much of the Brexit melodrama, the key factor is the internal politics of the Tory party. The Prime Minister may recognise the move is inevitable, but she is worried about the cries of betrayal from right-wing colleagues who will see an extension as a plot to stay in the EU. The clock is ticking.