Businesses are looking to Theresa May for assurances about life outside the EUOLIVIER MATTHYS/AP

There are still 63 week left before the UK leaves the EU, but the business world plans at least a year ahead and the ability to understand what the legal framework will look like after March 29, 2019 is crucial to commercial calculations.

“Brexit is perhaps the most intensively legal issue to affect the UK economy and British business for generations,” says Christopher McGee-Osborne of Dentons. “As lawyers to business it is incumbent on City law firms to participate, not spectate. Our clients tell us that what they seek is all about certainty and stability of regulation — that is the body of law, policy and the governance of changes to them that regulate business.”

Hot-air assurances from politicians will soon be given short shift.…