Big companies are stepping up their plans in case Britain crashes out of the European Union without a deal as Prime Minister Theresa May struggles to get talks back on track after a major setback.

Britain is aiming to agree with the EU on Dec. 14 to move the Brexit talks on to the second phase. This would focus on trade and a two-year transition deal to smooth the departure after March 2019. But the timetable has been thrown into doubt after discussions broke down in Brussels on Monday.

Senior executives in the financial services sector, which accounts for about 12 percent of the economy, told Reuters May's efforts to secure a transition deal had come too late and they had no choice but to start restructuring.