Sweden has said a UK vote to leave the EU would be “devastating on many levels”.
But, if worst comes to worst, the nation's Chamber of Commerce has said Sweden and capital Stockholm will be willing to offer themselves up as an “attractive alternative to the UK and London”.
The Chamber of Commerce email, signed by chief executive Maria Rankka and chief economist Andreas Hatzigeorgiou, said: "Brexit would be devastating on many levels, not only for the UK but especially for a country like Sweden.
"The UK is one of Sweden’s best allies in the EU. We stand together on a wide array of issues for a more free trade-oriented and competitive Europe. For Stockholm, Europe’s fastest-growing capital, the UK is our most important economic partner."
Saying that a vote for Remain is in Sweden's "direct interest", the letter added: "We will start planning for a future in which the UK has left the EU. In specific, Stockholm can strengthen its position as a hub for headquarters in the event of Brexit...
"We are convinced that companies with headquarters in the UK would have an interest in reviewing where they locate their operations in case the referendum leads the country away from the EU.
"Sweden and Stockholm would then be an attractive alternative to the UK and London."