Banks prep plans to flee amid Brexit

Finance executives said they are preparing for the worst on Brexit after Prime Minister Theresa May said on Tuesday that the United Kingdom will quit the European Union's single market.

"If you don't know where you are going, you have to plan for the worst and execute faster," HSBC Holdings Chairman Douglas Flint said in a speech at the World Economic Forum in Davos, Switzerland.

"This isn't rocket science. Businesses want to know, 'what is the ambition? And how does one deal with the transition? Is it the dreaded cliff edge or is there some kind of standstill'."