Comprehensive deals that cross all sectors of the economy are not simple matters. They must be negotiated in private with steely perseverance, excruciating attention to detail and steadfast patience. Tactical distractions, extraneous crises and negotiation fatigue are real dangers. They can only be mitigated with adherence to the longer-term strategy and an determination to dispense with diversions.

The role of business leaders in this process is critical. We worked closely with business groups to ensure that an eventual agreement with Europe would translate into better jobs and higher wages for Canadians. UK business leaders must now reach out to Prime Minister May to convey similar messages to the British people.

But while business can accurately point government to real gains and losses from international trade deals, it must never forget that the government has the broader interests of the population in mind. Political leaders will rise and fall with the support of that broader electorate, not with more narrow business concerns.