There’s no road map for European authorities facing the prospect of a British exit from their 28-nation union -- by design.

Officials in Brussels are under orders not to commit any scenarios to paper to avoid alarmist leaks, according to a senior official from one European government tasked with making preparations.

Given the potential political and financial shockwaves surrounding a Brexit vote, it’s not clear a map would do much good. Global markets are already sputtering as anxiety mounts about the impact on the world economy. EU President Donald Tusk goes so far as to say that it could spell the end of “western political civilization itself.”

Tusk’s exaggeration highlights the task in self-preservation awaiting European officials as they confront the potential departure of a country from the EU -- something that was inconceivable when the union was established. The mechanism for an exit was only written into law in 2009.

The first 24 hours

Before dawn on June 24, if an exit vote becomes clear, the EU’s top brass from Berlin to Brussels will be forced into damage control. In echoes of the Greek debt crisis, euro-area finance ministers may hold an emergency meeting as soon as that evening. Wild swings in the pound, more aggressive interventions by the Swiss National Bank and a ratcheting up of global instability rank as likely market reactions.

Currency markets haven’t priced in the U.K.’s exit from the EU, so if it happens, “a crash is pretty likely,” Lothar Mentel, chief executive officer of Tatton Investment Management in London, said on Bloomberg Television. “We would have to brace ourselves for quite a rough awakening on that Friday.”

David Fuller's view

Obviously no one knows precisely what markets will do at any given time of fear and uncertainty but they are a recipe for volatility.  Extreme forecasts, however over the top such as EU President Donald Tusk’s comment about the end of “western political civilization itself” (had he been listening to David Cameron?) are regarded as newsworthy.  I am sure Mr Tusk is sincere but it is probably a personal statement about his fears for his job, the EU and his country Poland.

There is also a degree of mischief about extreme forecasts from high-profile investment managers.  They are ‘talking their book’ and if short, have a vested interest in frightening other people so that they do not buy and perhaps even sell.  Conversely, in overextended bull trends they will talk up markets in pursuit of further profits.  

Additionally, a degree of chaos and intraday volatility is ideal for many high speed computer trading programmes which may account for most of the actual volume.      

My own view is that the widely anticipated Referendum, with its uncertain outcome, may be a case of ‘buy the rumour, sell the news’ for long trades, and ‘sell the rumour, buy the news’ for short positions. 

In the event of Brexit, I think the medium to longer-term consequences will be more tumultuous for the EU than for the UK.  Some would blame the UK for breaking up the EU.  Instead, I think Brexit would be a reality check for the EU superstate vision.  That could be positive over the longer term.