Bank of England Governor Mark Carney said on Monday that the possibility of Britain leaving the European Union next month without a transition deal ranked as the riskiest Brexit scenario for the stability of the financial services industry.

“The biggest issue from a financial stability perspective, from a market integrity perspective, from a continuity perspective, is a no-deal scenario by the end of March,” Carney said at a news conference.

Brexit is scheduled to take place on March 29 and lawmakers in London have yet to approve a deal that would smooth Britain’s departure from the EU, leaving open the prospect of a disorderly departure or a delay.