The London Stock Exchange has said it may move part of its business to the Netherlands if the UK crashes out of the European Union without a deal this week.
Its European platform Turquoise will shift euro-denominated share trading away from the UK, the exchange said.
However British, Swiss and US shares will stay on its existing London platform, it said.
And a potential hard Brexit on Friday would not mean the end of shares from the European Economic Area being traded in the capital, as they would likely trickle back to London over the course of the year.
It comes as Britain’s deadline for reaching a deal with the European Union is just days away.
MPs have defeated May’s agreement with the EU several times in recent weeks.
May has asked for the deadline to be extended until 30 June. Earlier today the country started preparing to take part in European Parliament elections in late May.