The timing within which Great Britain will leave the European Union has not yet been defined, but it is useless to pretend that Brexit might not happen: it is a remote scenario, which would further damage the already fragmented British political fabric.
The real challenge for Prime Minister May will rather be to protect the financial services sector, which is particularly developed in the United Kingdom and has grown thanks to the single European market.
The most important aspect to determine is the future of cross-border banking services, given that there are 489 foreign banks in London, of which 183 belong to the EU. Will they be able to continue to operate from London on the European market with the same regulation as today, or will they be forced to create subsidiaries (capitalised separately) to operate within the EU?
As for trade in industrial products, if Britain loses access to the single market it will probably have to contend with Community duties, which would induce multinationals to move their headquarters within the EU.
To solve the problem, former Prime Minister and Chancellor of the Exchequer Gordon Brown has suggested that the country can join the European Economic Area (EEA). In this case, however, London would have to continue to respect EU laws and contribute to the EU budget, at the same time losing the possibility of influencing European decisions.
From the point of view of the European Union, on the other hand, the damage that Brexit could cause can be divided into three levels. In the first place, the EU would lose an important economic partner, which is both a financial center and a key defense and security ally, as well as the main link with the United States.
The second potential risk is the political contagion. Brexit is the first significant setback to the European integration process since the Second World War, and Eurosceptic movements and parties across the EU are already taking the opportunity to step up their campaigns.
Finally, the third possible damage caused by Brexit consists in the acceleration of a phenomenon already underway: the tendency of EU countries to find intergovernmental solutions, which weaken the Community institutions rather than strengthen them (just think of the policies on migrants).
In this context, relations between the center and the periphery of the EU are fraying mainly due to low growth and the low level of interest rates. It should be immediately evident (but unfortunately it is not, at least for some member countries) that it will be impossible to ease these tensions until growth will not find a more central role in European politics.
To overcome the limitations imposed on individual countries by budget parameters, one could resort to a broad European investment plan financed by the EU through collective bonds. The refusal to use these instruments for public investment is unfair in economic terms, because it implies that the current generation must fully finance projects that will bear fruit even in the distant future.
It is necessary to understand that the solution to today's difficulties it is not in the decentralization of the decision-making process, but in its greater centralization, for example by creating a European Ministry of Finance.
As regards the economic and monetary union and the banking union, the European deposit guarantee – on which negotiations are currently frozen – is crucial to protect the Eurozone from a possible liquidity crisis in the banks of a single country. Especially since at the moment investors seem ready to launch a new speculative attack against peripheral banks and the Italian referendum on institutional reforms could provide them with the pretext in the event that the No vote wins, plunging the country into political instability.
Ultimately, a functioning economic and monetary union cannot do without new risk-sharing arrangements. An objective that can only be achieved through rigorous budgetary discipline and the "no-bail out" rule. Once all these elements are assembled, any negative shocks will no longer threaten the very survival of the union and the system will finally be stable.
