Brexit Secretary David Davis told a House of Commons committee on Wednesday that the nation should be prepared for a profound shift in the way the economy operates on a scale similar to that of the 2008 financial crisis.
Quizzed by panel chairman Hilary Benn at a hearing of the Exiting the European Union Committee, Mr Davis said the United Kingdom government has examined the ramifications for United Kingdom industries from Brexit.
He said the government had produced a "sectoral analysis" of different industries but not a "forecast" of what would happen when the United Kingdom leaves the EU.
Davis said an "impact assessment" was a formal Whitehall term for a document and they did not exist when it came to Brexit.
'There's no systematic impact assessment I'm aware of, ' Davis told the parliamentary committee.
"No", Davis replied, explaining that such models were "not as straightforward as people imagine" due to the many variables. However he reiterated that publishing a series of sectoral impact studies would undermine the UK's negotiating position and potentially reveal sensitive information.
"Sectoral analysis was used for a real reason, it's the analysis of what the sector looks like".
"I'm not a fan of economic models because they have all proven wrong".
British Foreign Secretary Boris Johnson says Brexit negotiations must not be held up by disputes over Irish borders and that the issue should be tackled in phase two of departure talks.
And in October, he told the Brexit committee that Prime Minister Theresa May had read "summary outcomes" of impact assessments, which he said went into "excruciating detail".
People seem to assume an impact assessment consists of a quantitative forecast.
"The free trade agreements carried out by the European Union have not been particularly beneficial to the United Kingdom", he said. The Queen famously asked why did we not know. "Whether it is through incompetence or insincerity, David Davis has been misleading Parliament from the start".
Mr Davis has already risked stoking tensions inside his Conservative party by suggesting that some forms of regulatory alignment with the European Union may be possible after the United Kingdom leaves the EU.