On Brexit, it is now time for business executives to move from the politics to the practicalities.

Assuming that Brexit is happening and there will be negotiations between the UK and the rest of the EU, executives need to identify what their company and their sector require to emerge from those negotiations.

Executives need to compile a shopping list of what needs to remain or change in the post-Brexit environment.

The question to ask is: "what do we need to ensure that this business continues with minimal interruption?" Answering that question involves identifying the ways in which EU law and practice currently help the company or sector to trade more easily. Put another way, what would be the legal obstacles that would have to be overcome post-Brexit?

The shopping list could comprise of, for example, provisions on licensing, authorisation, passporting, movement of people, mutual recognition of qualifications or standards as well as tariffs/fee-free arrangements.  One wants to avoid tariffs or charges but also obstacles to the business actually trading.  Some businesses may even need State aid or restructuring aid to deal with the seismic changes.

Businesses and sectors could then brief governments on their shopping lists to try to ensure that those lists are part of the negotiating agenda.

Briefing one's own government is critical but briefing other governments is also important.  They may also see the benefit for their own industry too.  And a critical mass needs to be built up because the negotiations will be complex: there are 27 remaining EU Member States, 3 European Economic Area States, a host of EU institutions, national parliaments and a plethora of lobbying groups.

Briefing the UK government is critical because there is an obvious tactical value in any negotiation, where one is not present, to create a situation where both sides of the table are calling for the same result.  The UK has the advantage of not wanting to damage industry either (provided UK industry is not affected) so it may be a powerful ally.

It would also be important to brief the European Commission because it needs to know what will help a business that is remaining within the EU.

Keeping EU law in mind is critical in the compilation of the shopping list and the negotiation of the deal.  EU law constrains what the EU and the remaining Member States may do in the negotiations.  For example, there cannot easily be special bilateral deals, discrimination or breaches of existing EU law.  Equally, there are ways in crafting and presenting arguments which are compatible with EU law and are more likely to succeed. There is no point in compiling a wonderful wish list which cannot be delivered under EU law. It needs to be EU law proofed.

Any lobbying needs to comply with EU and national lobbying rules.

Equally, such lobbying needs to comply with competition law - for example, competitors must not exchange competitively sensitive information.

As we move from the politics to the practicalities, it is time to move from the shock to the shopping list to protect businesses and the jobs in those businesses.